US President Donald Trump on Wednesday evening signed a proclamation to ban travel from a total of 19 countries, citing significant national security risks to the United States, administration officials confirmed to CBS News.

The new restrictions are targeted at specific nations and include provisions for various exceptions.

The proclamation imposes full restrictions on the entry of nationals from 12 countries: Afghanistan, Myanmar, Chad, the Republic of the Congo, Equatorial Guinea, Eritrea, Haiti, Iran, Libya, Somalia, Sudan, and Yemen.

Additionally, the entry of individuals from seven other countries will be partially restricted: Burundi, Cuba, Laos, Sierra Leone, Togo, Turkmenistan, and Venezuela.

White House spokeswoman Abigail Jackson emphasized the administration's rationale, stating to CBS News, "President Trump is fulfilling his promise to protect Americans from dangerous foreign actors that want to come to our country and cause us harm. These commonsense restrictions are country-specific and include places that lack proper vetting, exhibit high visa overstay rates, or fail to share identity and threat information. President Trump will always act in the best of interest of the American people and their safety."

Administration officials further elaborated that the measure was undertaken due to a "high level of risk to the United States."

The new travel ban allows for a range of exceptions, according to CBS News. These include lawful permanent residents, adoptions, dual nationals traveling on a passport from an unrestricted country, Afghan Special Immigrant Visas, and foreign nationals holding diplomatic, UN, or NATO visas.

Also exempt are athletes or members of athletic teams, including coaches and support staff, and athletes traveling for major sporting events such such as the World Cup or Olympics. Immediate family member immigrant visas, Special Immigrant Visas for US government employees, immigrant visas for ethnic and religious minorities in Iran, and other national interest exceptions will also be permitted.

The announcement of these travel restrictions comes in the wake of Sunday’s terrorist attack in Boulder, Colorado, on peaceful marchers who were raising awareness for Israelis taken hostage by Hamas.

The suspect in the attack, 45-year-old Mohamed Sabry Soliman, is an Egyptian national who entered the US in August 2022 on a tourist visa that expired in February 2023. He later filed for asylum in September 2022 and was granted a work authorisation in March 2023, but that also expired.

Trump blamed the policies of his predecessor, former President Joe Biden, for the attack in Boulder.

Trump wrote on his Truth Social that Soliman “came in through Biden’s ridiculous Open Border Policy, which has hurt our Country so badly. He must go out under 'TRUMP' Policy. Acts of Terrorism will be prosecuted to the fullest extent of the Law. This is yet another example of why we must keep our Borders SECURE, and deport Illegal, Anti-American Radicals from our Homeland. My heart goes out to the victims of this terrible tragedy, and the Great People of Boulder, Colorado!"