There are also seven additional countries whose nationals will face a partial travel restrictions.
The US president said the list could be revised if “material improvements” were made and additional countries could be added as “threats emerge around the world”.
This is the second time he has ordered a ban on travel from certain countries.
He signed a similar order in 2017, during his first term in office.
Which countries are affected?
Trump has signed a proclamation banning travel to the US from nationals of 12 countries:
- Afghanistan
- Myanmar
- Chad
- Congo-Brazzaville
- Equatorial Guinea
- Eritrea
- Haiti
- Iran
- Libya
- Somalia
- Sudan
- Yemen
Nationals from these countries will not be allowed to enter the US unless they qualify for an exception.
There are an additional seven countries whose nationals face partial travel restrictions:
- Burundi
- Cuba
- Laos
- Sierra Leone
- Togo
- Turkmenistan
- Venezuela
Countries hit by the partial restrictions will not be able to travel to the US with certain visas.
The ban takes effect on Monday at 12:01 (05:01 BST), a cushion that avoids the chaos that unfolded at airports nationwide when a similar measure took effect with virtually no notice eight years ago. No end date has been provided; the order calls for periodic review.
Why has a ban been announced?
The White House said these “common sense restrictions” would “protect Americans from dangerous foreign actors”.
In a video posted to his Truth Social website, Trump said the recent alleged terror attack in Boulder, Colorado “underscored the extreme dangers” posed by foreign nationals who had not been “properly vetted”.
Twelve people were injured in Colorado on Sunday when a man attacked a group gathering in support of Israeli hostages, throwing two incendiary devices and using a makeshift flamethrower.
The man accused of carrying out the attack has been identified as an Egyptian national, but Egypt is not included on the list of banned countries.
Trump has close ties with Egyptian President Abdel Fattah al-Sisi, who has in the past been described by the US president as his “favourite dictator”.
Only two of the 19 countries are on the US government’s State Sponsors of Terrorism list – Iran, which has a full ban, and Cuba, which has partial travel restrictions.
But national security is given as a partial reason for his choice of countries.
In the proclamation, Trump said many of these countries listed have a “historic failure to accept back their removable nationals” for the US, as well as having “taken advantage” of the US by exploiting its visa system.
He added that nationals from certain countries also “pose significant risks” of overstaying their visas.
What exemptions are there?
There are a number of people from affected countries who may still be able to enter the US due to a number of exceptions. The order does not apply to:
- “Lawful permanent” US residents
- Their immediate family members who hold immigrant visas
- US government employees with Special Immigrant Visas
- Adoptions
- Dual nationals when the individual is not travelling on a passport from one of the affected countries
- Afghan nationals holding Special Immigrant Visas
- Holders of “immigrant visas for ethnic and religious minorities facing persecution in Iran”
- Foreign nationals travelling with certain non-immigrant visas
- Athletes, their teams (including coaches and supporting staff), and their immediate family when travelling for major sporting events, such as the men’s football World Cup in 2026 and the Summer 2028 Olympics in Los Angeles.
In addition, the Secretary of State may grant exemptions to individuals on a “case-by-case” basis, if “the individual would serve a United States national interest”.
What has been the reaction to the ban?
Trump’s latest order, which is expected to face legal challenges, drew a swift response, at home and abroad.
Somalia promised to work with the United States to address any security issues.
In a statement, Somali ambassador to the US, Dahir Hassan Abdi, said his country “values its longstanding relationship” with America.
Venezuela’s Interior Minister Diosdado Cabello warned that “being in the United States is a great risk for anyone, not just for Venezuelans”.
The African Union, which represents all 55 countries on the African continent, called on the US to “engage in constructive dialogue with the countries concerned”.
It appealed to the US to exercise its sovereign right to protect its borders and its citizens’ security “in a manner that is balanced, evidence-based, and reflective of the long-standing partnership between the United States and Africa”.
The union said it remains concerned about the “potential negative impact of such measures”.
Democrats were quick to condemn the move.
“This ban, expanded from Trump’s Muslim ban in his first term, will only further isolate us on the world stage,” Pramila Jayapal, a Democrat congresswoman from Washington, says in a social media post.
Another Democrat, congressman Don Beyer, says Trump “betrayed” the ideals of the US’ founders.
Human rights groups have also criticised the ban.
Amnesty International USA described it as “discriminatory, racist, and downright cruel”, while the US-based Human Rights First, called it “yet another anti-immigrant and punitive action taken” by the president.
What happened last time?
Trump ordered his original travel ban during his first term in the White House in 2017.
It featured some of the same countries as his latest order, including Iran, Libya and Somalia.
Critics called it a “Muslim ban” as the seven countries initially listed were Muslim majority, and it was immediately challenged in courts across the US.
The White House revised the policy, ultimately adding two non-Muslim majority countries, North Korea and Venezuela.
It was upheld by the Supreme Court in 2018.
President Joe Biden, who succeeded Trump, repealed the ban in 2021, calling it “a stain on our national conscience.”