Following a deadly terrorist attack in Manhattan this week, President Trump said he has directed the Department of Homeland Security to boost its “extreme vetting” procedures for foreign nationals seeking entry to the U.S.

Trump said the alleged driver in Tuesday’s truck attack that killed eight people and injured 11 in New York City entered the country through the diversity visa lottery and said Congress should end the program immediately. The diversity lottery is open to people from countries with low levels of immigration to the U.S. Law enforcement officials said the driver of the truck is an Uzbek immigrant who entered the U.S. in 2010 and has lived in Tampa and New Jersey.

Trump said this week that the driver of the truck in Manhattan should get the death penalty, and that the government must “step up” its vetting procedures for foreigners who want to enter the country. “Being politically correct is fine, but not for this!,” Trump tweeted this week.

The White House said “extreme vetting” procedures should include enhanced collection and review of biometric and biographical data; improved documentation requirements and verifications; improved information sharing with other nations and foreign intelligence services; and heightened Customs and Border Patrol review procedures.

“Extreme vetting is, we simply interview people and have to satisfy ourselves that the person we’re talking to is indeed the person who they claim,” said White House Chief of Staff John Kelly in an interview this week. “It might be impossible to do in some cases. If we can’t verify, I don’t think we should let them into the country.”

Rep. Adam Schiff (D-CA) said Trump is using a horrible tragedy to bolster his case for more security. “To use this tragedy in that way to push an agenda is not what the president ought to be doing right now,” Schiff said.