Trump admin live updates: Dems react to Hegseth discussing Yemen strike in 2nd chat

Dan Caldwell, a senior adviser to Defense Secretary Pete Hegseth, has been placed on administrative leave as part of a leak investigation, a U.S. official told ABC News on Tuesday.

Caldwell is a longtime adviser to Hegseth, long before he was named to be the secretary of defense, and was placed on leave following an "unauthorized disclosure," Reuters reported.

On March 21, Joe Kasper, the Defense Department’s chief of staff, directed the "Director for Defense Intelligence (Counterintelligence, Law Enforcement, and Security) to support OSD in leading an investigation into unauthorized disclosures of sensitive and classified information across the Department of Defense."

That memo authorized the use of polygraphs that will be inline with "applicable law and policy" for an investigation that he said would begin immediately.

It is unclear if Caldwell underwent a polygraph.

-ABC News' Luis Martinez

Asked if Russia agreed to anything in its meeting with U.S. special envoy Steve Witkoff, White House press secretary Karoline Leavitt said she didn't want to get ahead of those negotiations but added that there is an "incentive" for Russia to end its war on Ukraine.

Trump spoke with the sultan of Oman Tuesday, who helped facilitate talks between the United States and Iran over the weekend, Leavitt confirmed during the briefing.

"As you know, an additional negotiation between Steve Witkoff and Iran's representative has been scheduled for Saturday. And since these are ongoing negotiations, I have nothing more to add on that," she added.

-ABC News' Molly Nagle

White House press secretary Karoline Leavitt mocked former President Joe Biden when asked about his speech Tuesday night that is focused on protecting social security.

"My first reaction when seeing former President Biden was speaking tonight was I'm shocked that he is speaking at night time. I thought his bedtime was much earlier," she said.

She then defended President Donald Trump's Social Security policy.

"President Trump is absolutely certain about protecting Social Security benefits for law-abiding, taxpaying American citizens and seniors who have paid into this program," she said.

White House press secretary Karoline Leavitt was pressed by reporters about the White House defying court orders to return Kilmar Abrego Garcia from the El Salvador prison where he is reportedly being held. She was asked by ABC News' Karen Travers who is responsible for Abrego Garcia.

Leavitt claimed the administration is complying with court orders.

She repeated unproven claims that the Maryland man was a member of MS-13 and involved in trafficking, citing the president and El Salvador President Nayib Bukele.

"There is never going to be a world in which this is an individual who's going to live a peaceful life in Maryland," Leavitt said.