WASHINGTON, Jan 15 (Reuters) - The United States on Wednesday imposed hundreds of sanctions targeting Russia, seeking to increase pressure on Moscow in the Biden administration's final days and protect some sanctions previously imposed.

The U.S. State and Treasury departments imposed sanctions on over 250 targets, including some based in China, taking aim at Russia's evasion of U.S. sanctions and its military industrial base.

As part of the action, the Treasury imposed new curbs on almost 100 entities that were already under sanctions, potentially complicating any future efforts to remove the measures.

Russia's embassy in Washington did not immediately respond to requests for comment.

The Treasury in a statement said Washington was imposing fresh sanctions on almost 100 critical Russian entities - including Russian banks and companies operating in Russia's energy sector - that were previously sanctioned by the United States. It said the move increases secondary sanctions risk for them.

The new sanctions are issued under an executive order that a senior Treasury official said requires Congress to be notified before any of the actions can be reversed.

Jeremy Paner, a partner at the law firm Hughes Hubbard & Reed, said the actions are "Trump-proofed," preventing reversal of the additional sanctions without congressional approval.

"You can't just with the stroke of a pen remove what's being done," he said.

Edward Fishman, a former U.S. official who is now a research scholar at Columbia University, called it a "very significant action."

"It protects these sanctions against sort of any frivolous decision to lift them," he said. "It gives the new Trump administration more leverage with Russia."

Trump's transition team did not immediately respond to a request for comment.

It was unclear how Donald Trump, who succeeds President Joe Biden on Monday, will approach the issue of sanctions on Russia. Trump has been friendly toward Russian President Vladimir Putin in the past and said on Monday that he would aim to meet quickly with him to discuss Ukraine.

When asked about his strategy to end the war, Trump told Newsmax: "Well, there's only one strategy and it's up to Putin and I can't imagine he's too thrilled about the way it's gone because it hasn't gone exactly well for him either."

Photo from Reuters