Updated

President Trump on Wednesday accused Senate Democrats of blocking and slow-walking “hundreds” of nominations of ambassadors and judges, saying the resulting situation is the “worst in U.S. history!”

Trump has repeatedly blasted Democrats for blocking his nominees, particularly former U.S. spokesman at the U.N. Richard Grenell, whom Trump has tapped for Ambassador to Germany. Grenell was nominated in September.

On Tuesday Trump said that many important positions are “unfilled because of this obstruction.”

The tweet comes as the administration gears up for two potentially contentious confirmation battles after Trump ousted Rex Tillerson as secretary of state on Tuesday. He has tapped CIA Director Mike Pompeo to replace him, and current Deputy Director Gina Haspel to replace Pompeo.

Both are likely to face a tough grilling, with Haspel certain to face significant scrutiny over the use of waterboarding against suspected terrorists at a CIA black site in Thailand during President George W. Bush's adminstration.

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With Republicans’ Senate majority tightened after their defeat in the Alabama Senate election in December, getting controversial nominees through will likely be tougher in 2018.

Trump also tweeted on the topic Sunday, saying that the “Senate must approve [his nominees] NOW!”

Last month, White House Press Secretary Sarah Sanders described the situation as “out of control.”

“[Senate Minority Leader Chuck] Schumer's tactics have led to 73 fewer confirmations than the next closest administration,” she said. “Half of President Trump's nominees are still waiting for confirmation in the Senate.”