US President Donald Trump instituted a long-anticipated travel ban on Thursday, prohibiting US entry to citizens from 12 countries and restricting the entry of citizens from seven others.

Trump’s proclamation “fully” restricts nationals from largely African and Muslim countries, including Afghanistan, Chad, the Republic of the Congo, Equatorial Guinea, Eritrea, Haiti, Iran, Libya, Somalia, Sudan, Yemen, and Myanmar from entering the US.

It also partially restricts nationals from Burundi, Cuba, Laos, Sierra Leone, Togo, Turkmenistan, and Venezuela.

In a video he released on social media on Thursday, Trump said the Colorado attack had “underscored the extreme dangers posed by foreign nationals who are not properly vetted”. The suspect in the attack is alleged to be an Egyptian national who overstayed his visa and previously lived in Kuwait.

Rumors had been circulating for months about what countries would be on the list after Trump signed an executive order on 20 January and gave the US State Department 60 days 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”.