President Donald Trump has signed a new Proclamation further restricting the entry of foreign nationals into the United States, adding 15 additional countries to the list of those facing partial travel limitations.

The move was made on Tuesday as part of ongoing efforts to tighten U.S standards for travel.

The newly added countries include Angola, Antigua and Barbuda, Benin, Côte d’Ivoire, Dominica, Gabon, The Gambia, Malawi, Mauritania, Nigeria, Senegal, Tanzania, Tonga, Zambia, and Zimbabwe.

The Proclamation continues full restrictions on the original 12 high-risk countries: Afghanistan, Burma, Chad, Republic of the Congo, Equatorial Guinea, Eritrea, Haiti, Iran, Libya, Somalia, Sudan, and Yemen.

It also imposes full restrictions on five additional countries based on recent security analyses: Burkina Faso, Mali, Niger, South Sudan, and Syria, as well as individuals holding Palestinian-Authority-issued travel documents. Two countries previously under partial restrictions Laos and Sierra Leone are now subject to full restrictions. Meanwhile, partial restrictions remain for Burundi, Cuba, Togo, and Venezuela.

The Proclamation lifts nonimmigrant visa bans for Turkmenistan, citing improved cooperation with the U.S., while maintaining restrictions on immigrant visas for its nationals.

Exceptions are provided for lawful permanent residents, current visa holders, certain visa categories such as athletes and diplomats, and individuals whose entry serves U.S. national interests.