Story highlights Donald Trump Jr.'s testimony has been sought by three committees on Capitol Hill

Trump Jr. met with Senate Judiciary Committee staff in September

(CNN) Donald Trump Jr. has agreed to meet with the House Intelligence Committee as soon as next week, giving lawmakers their first opportunity to question President Donald Trump's eldest son over his contacts with Russians during the campaign season, according to multiple sources with knowledge of the matter.

Trump Jr.'s highly anticipated testimony, scheduled for December 6, comes as he has faced growing questions on Capitol Hill about the June 2016 meeting at Trump Tower where he met with Russian operatives after being promised dirt on Democratic presidential candidate Hillary Clinton.

Both the House and Senate Intelligence Committees have interviewed several of the participants in the meeting, including on Tuesday when the House panel questioned the Russian translator, Anatoli Samochornov, who also attended the Trump Tower session, sources said.

But Trump Jr.'s appearance will be one of the most anticipated events yet of the investigation, particularly in light of new revelations of correspondence he had with WikiLeaks during the campaign season.

Senate Intelligence Chairman Richard Burr of North Carolina told CNN Wednesday that his panel planned to interview Trump Jr. in December, though he declined to give a specific date. He said the President's son was one of numerous witnesses the committee will be talking to next month as part of a packed schedule before the end of the year.

Read More