President Trump said Friday he wanted to go in a “tougher direction” after he unexpectedly withdrew the nomination for Ron Vitiello to lead Immigration and Customs Enforcement.

“We’re going in a little different direction. Ron is a good man, but we’re going in a tougher direction,” Trump told reporters before traveling to California to visit the U.S.-Mexico border. “We want to go in a tougher direction.”

Trump has not revealed who he plans to nominate instead of Vitiello, whose nomination he pulled on Thursday.

Vitiello, a longtime border official, was nominated the lead the federal agency after spending more than three decades in law enforcement. He will remain acting director for the time being.

He was expected to travel with Trump to the border Friday but is no longer joining the president, the Associated Press reported Thursday.

The change comes as the U.S. is seeing an increase in border crossings. Trump had threatened to close the southern border if Mexico did not stop illegal immigration and drug smuggling, but backed away from that threat Thursday, giving Mexico a “one-year warning” before possibly imposing tariffs on cars.

[Also read: Former ICE chief on denied asylum seekers: 'Arrest them, detain them, and remove them']