James Comey is scheduled to testify at 10 a.m. (1400 GMT) on Thursday as part of the committee's investigation into U.S. intelligence agency allegations that Russia tried to interfere with the 2016 presidential election and potential collusion by President Donald Trump's campaign. Russia has denied the allegations and Trump denies any collusion.

The committee posted Mr Comey's opening statement on its website on Wednesday:

"Chairman Burr, Ranking Member Warner, Members of the Committee. Thank you for inviting me to appear before you today. I was asked to testify today to describe for you my interactions with President-Elect and President Trump on subjects that I understand are of interest to you. I have not included every detail from my conversations with the President, but, to the best of my recollection, I have tried to include information that may be relevant to the Committee.

January 6 Briefing

"I first met then-President-Elect Trump on Friday, January 6 in a conference room at Trump Tower in New York. I was there with other Intelligence Community (IC) leaders to brief him and his new national security team on the findings of an IC assessment concerning Russian efforts to interfere in the election. At the conclusion of that briefing, I remained alone with the President-Elect to brief him on some personally sensitive aspects of the information assembled during the assessment.