Photo:Xinhua

Former US National Security Adviser John Bolton said Monday that he's willing to testify in the Senate trial of President Donald Trump's impeachment if subpoenaed.

"I have concluded that, if the Senate issues a subpoena for my testimony, I am prepared to testify," said Bolton, who left the White House in Sept. 2019, in a statement.

Bolton also said he has weighed the issues of executive privilege and that after "careful consideration and study" he has decided that he would comply with a Senate subpoena.

Bolton is one of several witnesses that Senate Democratic Leader Chuck Schumer has proposed calling for the trial of Trump's impeachment.

House Speaker Nancy Pelosi has not sent two articles of impeachment against Trump to the Senate in hope of giving Democrats more leverage to set rules for the trial, while Senate Majority Leader Mitch McConnell has so far rejected their demand.

It is unclear when Pelosi will release the articles, a move critical for the Senate to begin its trial.

McConnell has tweeted they can't hold a trial without the articles of impeachment, saying "the Senate's own rules don't provide for that."

The House, controlled by Democrats, impeached Trump for abuse of power and obstruction of Congress, last month.

Trump, who has denied any wrongdoing, on Monday slammed his impeachment case as a "hoax" and "witch hunt."

"The Impeachment Hoax, just a continuation of the Witch Hunt which started even before I won the Election, must end quickly," he tweeted. "It is a con game by the Dems to help with the Election!"

According to the nation's constitution, the House shall have the sole power of impeachment, while the Senate shall have the sole power to try all impeachments.

Conviction can only happen in the Senate and requires at least two-thirds of its members, or 67 senators, to vote in favor after a trial. Currently, the Senate has 53 Republicans, 45 Democrats and two independents.