Washington — Former national security adviser John Bolton said Monday he's willing to testify in President Trump's impeachment trial if the Senate subpoenas him.
"I have concluded that, if the Senate issues a subpoena for my testimony, I am prepared to testify," the former top aide to the president said in a statement on the website of his political action committee.
Bolton has firsthand knowledge of the events at the center of Mr. Trump's impeachment, namely efforts to pressure Ukraine to announce investigations that would benefit the president politically. He pushed back against the pressure campaign and at one point likened it to a "drug deal," according to earlier testimony by other officials.
Bolton's statement comes a week after a federal judge scrapped a case brought by Charles Kupperman, one of his former aides, to determine whether the House could compel him to testify. Bolton, who had been watching the case, was not formally subpoenaed by the House in the impeachment inquiry, and his lawyer threatened to go to court if he was.
"The House has concluded its constitutional responsibility by adopting Articles of Impeachment related to the Ukraine matter. It now falls to the Senate to fulfill its constitutional obligation to try impeachments, and it does not appear possible that a final judicial resolution of the still-unanswered Constitutional questions can be obtained before the Senate acts," Bolton said in his statement. "Accordingly, since my testimony is once again at issue, I have had to resolve the serious competing issues as best I could, based on careful consideration and study."
The prospect of Bolton's testimony is likely to put pressure on Senate Majority Leader Mitch McConnell and Republican senators to allow witnesses at a Senate trial, a move many GOP lawmakers have resisted. Democrats in the minority would need four Republicans to join them in voting to issue a subpoena.
The timing of a trial also remains uncertain. House Speaker Nancy Pelosi has yet to transmit the articles of impeachment to the Senate, and it's unclear if and when she will. Pelosi has demanded McConnell specify the procedures for the trial before she sends the articles to the upper chamber.
Senate Judiciary Committee Chairman and Trump ally Lindsey Graham said on Fox News that the Senate should change its rules to allow the trial to begin without Pelosi transmitting the articles.