Welcome to meet the press now. I'm Kristen Welker, and that was the closing bell on Wall Street on day six of the U.S. War with Iran.

Markets ending lower with the Dow at one point plunging more than 1,100 points, but came back to close roughly down 800 points amid growing uncertainty.

And the price of oil surging again. It has now gone up roughly 20% since the war began less than a week ago.

In just a few moments, we are expecting an update on the war from Defense Secretary Pete Hegseth and the top U.S.

military commander for the Middle East region. We will bring you that press conference when it begins.

But we begin with breaking news and that major shakeup in the Trump administration.

The president announcing on his social media feed this afternoon that he's firing Homeland Security

Secretary Christy Knoem and naming Oklahoma Senator Mark Wayne Mullen as his pick to replace her.

Senator Mullen was attending a Senate lunch when he got a call from the president telling reporters he was not expecting that call today. Take a look.

Listen, I am super excited about this opportunity. It came at a, not a complete surprise, but it came at a little bit of surprise for us.

You know, the Department of Homeland Security has a very broad jurisdiction.

And I think there's a lot of work that we need to do, and I'm excited about it. Senator Patterman says he's going to vote for you. Do you expect other Democrats to vote for you?

John already text me, and of course, you guys know John and our friends too.

And so I don't know. We're going to try to earn everybody's vote.

I want people to understand. I'm not, when I go into this position, yes so I don't know. We're going to try to earn everybody's bloated. I want people to

understand. I'm not, when I go into this position, yes, I'm a Republican. Yes, I'm conservative.

But Department of Homeland Security is to keep everybody. Regardless if you support me, if you don't

support me, regardless of what your thoughts are. Now, the move comes as several sources tell NBC News,

the president was unhappy with Secretary

Nome's testimony this week before House and Senate committees, including this exchange.

The president approved ahead of time you spending $220 million running TV ads across the country in which you are featured prominently.

Yes, sir. We went through the legal processes. Did it correct? Did the president know you're

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