President Trump on Wednesday demanded that Immigration and Customs Enforcement officers continue to stop vehicles despite a spate of fatal shootings that had led to a temporary halt to the practice just a day before.

In a post on social media, Mr. Trump defended the traffic stops and urged ICE to “go back and do your very important job.”

“We CANNOT give up one of I.C.E.’s most important and effective Crime Fighting tools, THE TRAFFIC STOP!” Mr. Trump wrote. “Once we do, we are playing right into the criminal’s hands.”

The temporary pause on vehicle stops came on Tuesday, after ICE agents shot and killed one person in Houston and another in Biddeford, Maine, over the past week as part of a recent surge in immigration arrests. Both people were killed after officers tried to stop their cars, according to the Department of Homeland Security.

The department did not immediately respond to a request for comment on Mr. Trump’s post.

Tom Homan, the White House border czar, tried to downplay the potential impact of the pause on Tuesday, saying it was a temporary measure to “make sure we’re doing the right thing.” But many arrests occur after ICE officers pull over people in their cars, and the pause threatened to hamper the agency’s ability to increase arrests at a time when the White House and Mr. Trump’s conservative supporters are pressuring it to ramp up deportations.

Some influential lawmakers had urged Markwayne Mullin, the homeland security secretary, to impose the pause, including Senator Susan Collins of Maine, a Republican seeking re-election this year.