Sen. Jack Reed, D-R.I., brought up the situation in Los Angeles and questioned Defense Secretary Pete Hegseth about the administration's use of National Guardsmen and Marines to deal with the protests.

The senator said this week the Dept. Homeland Security sent a request to the Defense Department "to authorize military forces to detain or arrest American citizens, to provide D.H.S. with military drone surveillance support and to have the Marine Corps advise D.H.S. on running joint operations."

"Every authorization we provided the National Guard and the Marines in Los Angeles is under the authority of the president of the United States is lawful and constitutional," Hegseth said.

Hegseth argued that the military use in the city was part of an effort to maintain "law and order," but the senator pushed back.

"Law and order is a civil function under the Constitution of the United States. Civil enforcement, law enforcement authorities, not the U.S. military," Reed said.

"This is not only, I think, illegal, but also a diminution of the readiness and focus of the military," he added.

Republican Sen. Mitch McConnell, a critic of the Trump administration's handling of the Russia-Ukraine war, focused his questions to Defense Secretary Pete Hegseth on the conflict.

McConnell asked Hegseth who is the aggressor and who is the victim in the conflict. Hegseth said that Russia is the aggressor, but declined to include in his answer whether he viewed Ukraine as the victim.

McConnell also asked Hegseth which side he wanted to win the war, to which Hegseth responded that the Trump administration wants to see "peace."

"Ultimately peace serves our national interests," Hegseth said.

Elon Musk early on Wednesday said that he regrets some of the posts he made about President Donald Trump late last week, saying he went "too far."

"I regret some of my posts about President @realDonaldTrump last week," Musk said in a post on X, his social network. "They went too far."

Musk did not clarify which posts he was referring to in his statement.

-ABC News' Alex Ederson

A federal appeals court will allow President Donald Trump's reciprocal tariffs to remain in effect temporarily.

The United States Court of Appeals for the Federal Circuit continued a stay of a ruling from the Court of International Trade that blocked the president's sweeping global tariffs last month.

"Both sides have made substantial arguments on the merits. Having considered the traditional stay factors, the court concludes a stay is warranted under the circumstances," the court's two-page decision said.

The court also granted expedited review of the appeal with oral arguments set for July 31.

-ABC News' Peter Charalambous