President Donald Trump on Monday weighed in on the ICE detention of Mahmoud Khalil, a leader in Columbia University's encampment movement who he said was a "Radical Foreign Pro-Hamas Student."

"We know there are more students at Columbia and other Universities across the Country who have engaged in pro-terrorist, anti-Semitic, anti-American activity, and the Trump Administration will not tolerate it. Many are not students, they are paid agitators. We will find, apprehend, and deport these terrorist sympathizers from our country -- never to return again," Trump posted on Truth Social.

Trump added that the White House "expect[s] every one of America's Colleges and Universities to comply."

ICE arrested Khalil over the weekend, claiming that his student visa had been revoked, according to attorney Amy Greer in a statement to ABC News. However, Khalil is in the United States on a green card and not on a student visa, Greer said.

-ABC News' Molly Nagle

Secretary of State Marco Rubio, talking to the media as he traveled to Saudi Arabia for peace talks with Ukraine, said he expects the pause in U.S. military assistance to be a topic of Tuesday's conversation.

"I imagine that they'll raise that, and I'm sure that'll be addressed. And hopefully, we'll have a good meeting, and we'll have good news to announce on that front. I can assure you this, we will not be providing military aid to the Russians," Rubio said.

The secretary also said the U.S.-Ukraine mineral deal is continuing to be worked on but is not the primary focus of the meeting.

"Tomorrow can be successful without it," Rubio told reporters. "It's certainly a deal the president wants to see done but it doesn't necessarily have to happen tomorrow."

Secretary of State Marco Rubio took several questions from reporters as he flies to Saudi Arabia for peace talks with Ukrainian representatives. He said he hoped for a "positive interaction" and that the U.S. needs to hear Ukraine "clearly establish their intentions" to reach an agreement.

"And the most important thing that we have to leave here with is a strong sense that Ukraine is prepared to do difficult things, like the Russians are going to have to do difficult things, to end this conflict or at least pause it in some way, shape or form," he said.

Ontario Premier Doug Ford announced Monday a 25% increase on electricity exports to some American states as a result of President Donald Trump's tariffs on Canada.

"President Trump's tariffs are a disaster for the U.S. economy. They're making life more expensive for American families and businesses," Ford said at a news conference. He added, "Until the threat of tariffs is gone for good, Ontario won't back down. We'll stand strong, use every tool in our toolkit and do whatever it takes to protect Ontario."

Ford previously threatened to cut off electricity completely if Trump's trade war continues.