Democrats say Robert Mueller has agreed to testify publicly on July 17 before the House Judiciary and intelligence committees after both panels issued subpoenas to him on Tuesday evening.
House Judiciary Committee Chairperson Jerrold Nadler and House Intelligence Committee Chairperson Adam Schiff said in a joint statement that the special counsel has agreed to testify about the Trump-Russia report he issued in April.
The Justice Department declined to comment.
The committees have been in negotiations with Mueller for more than two months about his testimony. But he has been hesitant to testify and speak about the investigation beyond a public statement he issued last month.
In a letter to Mueller accompanying the subpoenas, the committee chairperson said "the American public deserves to hear directly from you about your investigation and conclusions".
In April, US Attorney General William Barr released a redacted version of Special Counsel Robert Mueller's report on Russia's role in the 2016 US presidential election.
Mueller did not conclude that Trump had committed obstruction of justice, but did not exonerate him either.
Barr subsequently concluded that Trump had not broken the law, but told a news conference that Mueller had detailed "10 episodes involving the president and discusses potential legal theories for connecting these actions to elements of an obstruction offence".