President Donald Trump on Monday lashed out at Rep. Adam Schiff (D-CA), the top Democrat on the House Intelligence Committee, just minutes before his son-in-law Jared Kushner was expected to speak to a congressional committee about Trump campaign contacts with Russia.

In a series of tweets Monday morning, Trump labeled Schiff as "sleazy" and called on "beleaguered" Attorney General Jeff Sessions to investigate Hillary Clinton's connections with Russia.

On Monday, Kushner released a statement ahead of his testimony before the Senate Intelligence Committee, which was not expected to be given under oath.

Schiff said in an interview over the weekend that Trump is "clearly worried" that Special Counsel Robert Mueller will look into the Trump Organization's business dealings to determine if the company had participated in Russian money laundering schemes.