WATCH: Sean Spicer holds daily White House press briefing

Update: This event has ended.

White House press secretary Sean Spicer is set to address the press corps on Monday just one hour before ex-Obama officials testify before Congress on Trump-Russia allegations.

Both Sally Yates and James Clapper will testify on Monday in a Senate investigation into allegations of Russian meddling in the 2016 U.S. election and possible collusion between President Donald Trump's campaign and Moscow.

President Trump sounded off on the hearing via Twitter on Monday, saying the committee should ask Yates "if she knows how classified information got into the newspapers soon after she explained it to W.H. Counsel."

Spicer's Monday briefing also comes as Trump is expected to announce 10 conservative federal court nominees.

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