The announcement follows a rapid tightening of immigration measures after investigators identified the suspect as a 29-year-old Afghan national who entered the country in 2021 through a post-withdrawal resettlement programme.
The President made the declaration on his Truth Social platform on Thursday night, arguing that the move was necessary to 'allow the US system to fully recover' and to reverse what he described as the 'millions of Biden illegal admissions.'
While he did not specify which nations fall under the label, the term 'Third World' is broadly associated with developing countries across the Global South.
Trump said his administration would move to remove 'anyone who is not a net asset to the United States' and pledged to strip federal benefits and subsidies from all non-citizens. He further vowed to denaturalise migrants deemed to threaten 'domestic tranquillity' or considered 'non-compatible with Western civilisation.'
The remarks come as the nation reels from Wednesday's attack near the White House, where two National Guard members were shot. One of them, 20-year-old Sarah Beckstrom, later died, while her colleague, 24-year-old Andrew Wolfe, remains in critical condition.
Authorities have named the suspect as Rahmanaullah (also known as Rahmanullah) Lakanwal, an Afghan who arrived under Operation Allies Welcome, a programme created to protect Afghans who had worked with US forces following the 2021 withdrawal from Kabul.
Federal officials confirmed that Lakanwal's immigration history, including his asylum approval earlier this year, is now under scrutiny by Homeland Security and the FBI. His case has quickly become a political flashpoint, bolstering Trump's long-held position that immigration poses significant national security risks.
Sweeping reviews ordered
Earlier on Thursday, US Citizenship and Immigration Services (USCIS) Director Joseph Edlow announced a 'full-scale, rigorous re-examination' of every green card issued to immigrants from 19 'countries of concern.' The list, based on a presidential proclamation from June, includes Afghanistan, Haiti, Iran, Myanmar, Venezuela, Yemen, Cuba, Somalia and others.
Edlow said the reassessment was being carried out 'at the direction of President Trump,' emphasising that 'the protection of this country and of the American people remains paramount.' USCIS has also indefinitely suspended all Afghan immigration requests pending updated vetting procedures.
The administration's wider review extends to roughly 200,000 refugees admitted under former President Joe Biden, with green card applications for those individuals frozen until further notice.
Trump has been steadily intensifying immigration restrictions throughout his presidency, but the Washington shooting has triggered an even more aggressive posture. In recent weeks, he has reinstated travel bans affecting several countries across Africa, Asia and the Middle East and set a historically low refugee cap of 7,500 for 2026.
On Thursday, he reiterated a call for 'reverse migration,' arguing that reducing what he termed 'illegal and disruptive populations' was essential to restoring public security. His administration has already expanded deportation operations, with ICE data showing that more than two-thirds of detainees arrested since mid-November had no criminal convictions.
While Lakanwal entered the country legally under a US-backed evacuation programme, Trump has pointed to the case as evidence that broader categories of legal migration require tighter vetting. He described the shooting as an 'act of terror,' insisting it underscored a longstanding failure in immigration policy.
The President has not clarified how a blanket pause on migration from 'Third World countries' would be defined or enforced, nor how it would interact with existing statutes on asylum, refugee protection, and family reunification. Legal experts warn that such sweeping restrictions may face court challenges, similar to battles seen during his first presidency over travel bans targeting majority-Muslim nations.
Wycliffe Nyamasege
