US President Donald Trump on Thursday declared that he will “permanently pause migration from all Third World countries”, following the shooting of two National Guard service members in Washington by an Afghan national.

Trump also warned that he plans to undo "millions" of immigration admissions approved under former President Joe Biden.

Trump’s declaration vowed not only to halt future migration but also to reassess millions of immigration admissions issued under the previous Biden administration, according to a report by the AFP. He said his plan would include deporting non-citizens who, in his words, fail to contribute or pose security concerns, and cutting off federal benefits for all non-U.S. citizens.

The comments are being seen as a dramatic intensification of the president’s second-term agenda, which has increasingly focused on mass removals and sharply restricted entry into the United States. Trump framed the move as necessary, and said, “Only REVERSE MIGRATION can fully cure this situation.”

Meanwhile, the US Citizenship and Immigration Services (USCIS) issued new policy guidance ordering a comprehensive re-examination of every Green Card belonging to individuals from nations classified as “high risk”. This comes after the attack by an Afghan national that killed US Army Specialist Sarah Beckstrom, 20, and US Air Force Staff Sgt Andrew Wolfe, 24, in Washington, DC, on Wednesday.

USCIS Director Joseph Edlow said the new directive is already in effect and will apply to all pending and future requests filed from November 27, 2025, onward, according to a report by news agency PTI. He added that “country-specific negative indicators” will now be used during security vetting.

The 19 countries designated under the updated scrutiny list are: Afghanistan, Myanmar, Burundi, Chad, the Republic of the Congo, Cuba, Equatorial Guinea, Eritrea, Haiti, Iran, Laos, Libya, Sierra Leone, Somalia, Sudan, Togo, Turkmenistan, Venezuela, and Yemen.

These same nations were included in a travel restriction order Trump issued earlier this year targeting perceived security threats.

The term “third world” is often used in political debates, but it is not an official term in US immigration rules. It first appeared during the Cold War when it described countries that were not aligned with either the United States or the Soviet Union.

Over time, people began using the term, often in the wrong way, to describe poor or developing nations. Many of the 19 countries on the new list fall into one of three groups which are low or middle-income nations, nations dealing with conflict or unrest, and nations that need stricter security checks.