“This is a president who believes it is OK for him to think that people who say something that will move this country forward should be deported. He’s called on us to go back and fight corruption and fight these countries that have worse leaders and inept leaders,” Omar said on the program Monday evening. “Well, we are living in one. He is that president. He is corrupt. He is the worst president we’ve had. He is inept and we are going to call him out for it, and we’re going to hold him accountable.”

Omar spoke with MSNBC’s Rachel Maddow for her first television interview since Trump posted a series of messages slamming her and her Democratic colleagues. During the segment, Omar lambasted the president for the “vile garbage that constantly comes out of his mouth” and said she had no plans to stop holding him in check.

Rep. Ilhan Omar (D-Minn.) called President Donald Trump the “worst” leader America has had on Monday, continuing an ongoing feud between the White House and members of Congress over a series of racist messages posted by the president this weekend.

We’re not just here to respond to the President’s tweets. We’re here to hold him fully accountable for his crimes and put forward a bold progressive agenda for this country. 💪🏽 pic.twitter.com/3DP3ip4hf5

Trump is embroiled in controversy over a series of vitriolic comments he made on Twitter in which he said a coalition of progressive lawmakers should “go back” to the countries they came from. The message was largely seen as an attack against a group of freshman lawmakers including Reps. Alexandria Ocasio-Cortez (N.Y.), Rashida Tlaib (Mich.), Ayanna Pressley (Mass.) and Omar.

Omar is the only one of the four who was not born in America: Her family emigrated from Somalia when she was a child, and she is now a U.S. citizen.

On Monday, Omar and her colleagues held a press conference to decry the president’s remarks, calling them “blatantly racist” and saying they were similar to those made by white nationalists. But Trump also spent the day doubling down amid the outcry, saying the four women “hate America” and that they could leave if they were unhappy with the state of things.

“If you hate our country, if you’re not happy here, you can leave,” the president said outside the White House. “You can leave. You can leave right now. Come back if you want. Don’t come back, that’s OK too. But if you’re not happy, you can leave.”

Omar told Maddow she hoped to hold the president accountable despite his attacks, saying that she has “to make sure to let him know that here in this country, we see everyone, we welcome everyone, and we remind people that they are valued.” She also renewed her call for impeachment proceedings.

“Look, we have a president that truly believes that if you say something that he doesn’t agree with, that you should no longer have the opportunity to exercise your First Amendment rights,” the lawmaker said. “Here we are as members of Congress doing the work that will get us the country we all deserve, one that is truly functioning for all of us, one that sees and values every single person in it and one that is making sure that our shiny and wonderful Constitution is fully intact and the protections offered is enjoyed by all of us.”