WASHINGTON, May 31 ― US President Donald Trump said yesterday that Border Patrol agents had apprehended the largest single group ever of undocumented immigrants, as he prepared what he said would be tough new measures to halt border crossers.

"Yesterday, Border Patrol agents apprehended the largest group of illegal aliens ever: 1,036 people who illegally crossed the border in El Paso around 4 am,” Trump said in a tweet.

Trump posted a Border Patrol video of scores of migrants crossing the Rio Grande riverbed from Ciudad Juarez, Mexico into El Paso, Texas.

They are only a small part of the 100,000-plus migrants, mostly Central Americans, who have crossed the Mexico frontier into the United States in recent months, frustrating officials tasked with halting illegal immigration.

Trump had said earlier yesterday that he was planning to make a "dramatic” statement on border policy to deal with what he called a "national emergency.”

"This is a big-league statement. We are going to do something very dramatic on the border,” he said.

Trump did not explain what he would do, but the Washington Post said he was considering slapping new trade tariffs on Mexico to force it to stop the northward flow of people fleeing poverty and violence in Guatemala, El Salvador and Honduras.

"It will be a statement having to do with the border and having to do with people illegally coming over the border,” Trump said. ― AFP