United States President Donald Trump signed a presidential proclamation on Wednesday banning citizens of 12 countries from entering the US. Heightened restrictions on entering the US have been put in place for nationals of seven more countries.

The travel ban is Trump’s latest move in the immigration crackdown that he promised on the campaign trail before last year’s presidential election.

Trump said the measures would help to “protect Americans from dangerous foreign actors”.

Here is what we know about the travel ban so far:

Which countries’ citizens are fully restricted from travelling to the US?

The 12 countries whose nationals are fully restricted from travelling to the US under Trump’s travel ban are:

• Afghanistan
• Myanmar
• Chad
• Republic of the Congo
• Equatorial Guinea
• Eritrea
• Haiti
• Iran
• Libya
• Somalia
• Sudan
• Yemen

Which countries are subject to partial restrictions?

The seven countries subject to partial restrictions are:

• Burundi
• Cuba
• Laos
• Sierra Leone
• Togo
• Turkmenistan
• Venezuela

How will Trump’s travel ban work?

Citizens from the 12 countries subject to a full ban on travel to the US will face a complete suspension of immigrant and non-immigrant visas.

Citizens from the seven countries which have been placed under partial restrictions will no longer be able to apply for immigrant visas or non-immigrant temporary visas covering permanent immigration, student visas and tourism visas including B-1, B-2, B-1/B-2, F, M and J. They will still be able to apply for some temporary visas, however.

Unlike an executive order, a presidential proclamation is not legally binding but generally signals a policy shift.

The new rules apply only to people outside the US at the time of the proclamation and who did not yet hold a valid visa at the time of the proclamation.

Are there any exceptions to the travel ban?

Yes. The new suspension and restrictions will not apply to:

• Lawful permanent residents of the US, also known as green card holders.
• Existing visa holders.
• Foreign diplomats travelling under certain non-immigrant visa categories.
• Dual nationals of the 19 countries included in the ban, if they are travelling on a passport of a country that is not subject to the ban.
• Athletes or members of an athletic team, such as coaches, people performing a support role and immediate relatives, travelling for a major sporting event such as the World Cup or Olympics.
• Immediate family immigrant visas (IR-1/CR-1, IR-2/CR-2, IR-5) “with clear and convincing evidence of identity and family relationship (eg DNA)”.
• Adoptees.
• Afghan Special immigrant visas.
• Special immigrant visas for US government employees.
• Immigrant visas for ethnic and religious minorities facing persecution in Iran.

How many people could this affect?

“Our analysis of State Department visa data shows the full ban on the 12 countries and partial ban on seven others could affect a sizeable number of people,” said Michelle Mittelstadt, director of communications at the Migration Policy Institute.

For citizens of the 12 fully banned countries, just more than 50,000 green cards were issued in fiscal year 2023, Mittelstadt told Al Jazeera, citing State Department data. On top of that, just more than 62,000 nationals from these countries were issued with temporary study, work or travel visas that year, giving a collective total of about 112,000 from those 12 countries in 2023.

The same year, citizens of the seven partially banned countries were issued with about 45,000 green cards and 69,000 temporary study, work or travel visas, giving a total of nearly 115,000 visas. Together, that makes more than 226,500 people.

According to Department of Homeland Security data, a total of 363,549 people from the 19 listed countries collectively entered the US in the previous year – 2022, its most recent year for records of arrivals into the US.

Some 250,234 of these people were from Venezuela, which is subject to partial restrictions only.

A further 66,563 of these people were from Haiti, which now faces a complete travel ban.

Who will be worst affected and could families be split up?

Anyone wishing to travel for study or tourism purposes will be affected, as well as anyone who had hoped to move to the US on a longer-term basis. But those who already live in the US could be impacted as well, experts say.

“Monthly data from fiscal year 2024 suggests that the Department of State issued up to 236,573 visas in categories likely to be affected by the travel ban,” said Cecilia Esterline, a senior immigration policy analyst at the Niskanen Center think tank based in Washington, DC. “If we anticipate a similar number of visas this year, the impact on families and employers could be significant.

“However, the proclamation includes several exemptions that could mitigate at least some of those effects, including exemptions for some spouses and minor children.”

Despite that, the new order is likely to cause a great deal of uncertainty for people already in the US, Mittelstadt said. “For citizens of these countries living in the US who are not naturalised citizens, the travel ban most likely will freeze them in place, as many will be fearful that they might not be permitted re-entry if they leave the US temporarily.”

Mittelstadt added that the travel ban could split families “given the inability to travel legally to the US or apply for a permanent or temporary visa, as well as the immobility this will confer on many citizens of these countries who are already in the US”.

Why has Trump banned arrivals to the US from these countries?

Trump cited security threats and “foreign terrorists” as grounds for the ban.

In a video posted on Wednesday on his social media platform, Truth Social, Trump said the recent attack in Boulder, Colorado “has underscored the extreme dangers posed to our country by the entry of foreign nationals who are not properly vetted, as well as those who come here as temporary visitors and overstay their visas”.

On June 1, police arrested a man who threw incendiary devices towards a group of people attending a rally for the release of captives taken from Israel on October 7, 2023 and held in Gaza. The FBI said it was investigating the incident as “an act of terror”.

Suspect Mohamed Sabry Soliman was charged with a federal hate crime, as well as an array of state charges, according to an affidavit by the US Department of Justice. Soliman is an Egyptian national who has also lived in Kuwait. Neither of these countries is on Trump’s list of banned countries.

In a Truth Social post, Trump blamed “[former US President Joe] Biden’s ridiculous Open Border Policy” for allowing Soliman into the country. Stephen Miller, the White House deputy chief of staff for policy, said the suspect in the Boulder incident had overstayed a tourist visa, without naming Soliman.

A fact sheet published by the White House stated a specific justification for the exclusion of each country on the new travel ban list.

These justifications included that large numbers of citizens had overstayed their visas, that the countries had a poor record of cooperating with the US to receive their citizens back if they had overstayed in the US, or that the countries were affected by war.

According to the most recent figures from the US Department of Homeland Security, nationals of Chad had the highest overstay rate, at 49.5 percent of those arriving in the US on a visa. Others with high overstay rates were Equatorial Guinea (22 percent), Eritrea (20 percent) and Yemen (19.8 percent).

On his first day in office, Trump signed an executive order, calling on his state department to identify countries “for which vetting and screening information is so deficient as to warrant a partial or full suspension on the admission of nationals from those countries”. He referred to this order in his video announcement of the travel ban.

When does the travel ban take effect?

The travel ban will take effect on June 9 at 12:01am EDT (04:01 GMT).

Has Trump done this before?

Yes, Trump enacted a travel ban – dubbed the “Muslim ban” as all but one of the countries on the list at that time were Muslim-majority – during his first term in 2017.

In his Wednesday Truth Social video, Trump said: “In my first term, my powerful travel restrictions were one of our most successful policies and they were a key part of preventing major foreign terror attacks on American soil.”

However, Mittelstadt from the Migration Policy Institute said: “We are unfamiliar with any prior evidence or public statements by the US government that the first-term travel bans prevented any terrorist attacks on US soil.

She explained that while much of intelligence and counter terrorism work is never made public, the first-term travel bans were criticised by some former, high-level intelligence and diplomatic officials who had served in both Republican and Democratic administrations.

In 2017, they issued a joint declaration, filed in the legal challenge to the original travel bans. In this declaration, they said that “banning travel from the original countries did not enhance national security and might even undermine counterterrorism efforts”, Mittelstadt said.

That earlier ban went through several revisions. It was upheld by the US Supreme Court in 2018. In 2021, Biden repealed this ban, calling it “a stain on our national conscience”.

Could more countries be added to this travel ban in the future?

Yes. In his Truth Social video announcement, Trump said “the list is subject to revision based on whether material improvements are made.

“Likewise, new countries can be added as threats emerge around the world.”

How are affected countries reacting to Trump’s travel ban?

The African Union, which includes seven of the 12 nations on the full travel ban list, said the ban would harm “people-to-people ties, educational exchange, commercial engagement, and broader diplomatic relations” that were built with the US over past decades.

“The African Union Commission respectfully calls upon the US administration to consider adopting a more consultative approach and to engage in constructive dialogue with the countries concerned,” the bloc said in a statement.

Chad responded by suspending visas for US citizens. In a Facebook post on Thursday, President Idriss Deby said: “I have instructed the government to act in accordance with the principles of reciprocity and suspend the issuance of visas to US citizens.”

“The high visa overstay rate for 2022 and 2023 is unacceptable and indicates a blatant disregard for United States immigration laws,” Trump’s proclamation stated.

Other African nations were more conciliatory, however. Dahir Hassan Abdi, the Somali ambassador to the US, said in a statement that Somalia is ready to work with the US. “Somalia values its longstanding relationship with the United States and stands ready to engage in dialogue to address the concerns raised,” he said.

Trump’s proclamation described Somalia as “a terrorist safe haven” and stated: “Somalia lacks a competent or cooperative central authority for issuing passports or civil documents and it does not have appropriate screening and vetting measures.”

Similarly, Sierra Leone’s information minister, Chernor Bah, said: “Our attitude to this is what more can we do? How can we collaborate with our US partners with whom we have and believe will maintain a very good relationship.”

Trump’s proclamation said Sierra Leone, which is now subject to partial restrictions, “has historically failed to accept back its removable nationals”.

Diosdado Cabello, Venezuelan interior minister and close aide of President Nicolas Maduro, said: “The truth is being in the United States is a big risk for anybody, not just for Venezuelans … They persecute our countrymen, our people for no reason.”

Trump’s proclamation stated: “Venezuela has historically refused to accept back its removable nationals.”