US President Donald Trump stepped up his attacks on his former national security adviser John Bolton, whose upcoming book could harm Mr Trump's impeachment trial defence.
Mr Bolton's book reportedly says that the president wanted to freeze military aid to Ukraine until Kiev opened an investigation into Mr Trump's political rival Joe Biden.
Democrats want Mr Bolton to testify at the president's ongoing Senate trial, and there have been growing indications that enough Republican senators could support the demand.
In an early-morning tweet, Mr Trump again attacked Mr Bolton - whom he fired in September – saying his former adviser had begged for the job and shown poor judgement.
Mr Trump said Mr Bolton "got fired because frankly, if I listened to him, we would be in World War Six by now."
"(He) goes out and IMMEDIATELY writes a nasty & untrue book. All Classified National Security. Who would do this?"
Calling Mr Bolton, and potentially other witnesses, to testify could prolong the impeachment trial and torpedo efforts by the White House to bring proceedings to a close this week.
The accusation that funds were withheld from Ukraine for Mr Trump's own political purposes was at the heart of his impeachment by the Democratic-controlled House of Representatives.
Four Republicans would need to join Democrats in the Senate, where Republicans hold a 53-47 edge, to allow testimony from Bolton and others.
Mr Trump's former White House chief of staff, retired general John Kelly, yesterday threw further doubt on Mr Trump's conduct.
"If John Bolton says that in the book, I believe John Bolton," Kelly said.
Why didn't John Bolton complain about this "nonsense" a long time ago, when he was very publicly terminated. He said, not that it matters, NOTHING!
— Donald J. Trump (@realDonaldTrump) January 29, 2020
For a guy who couldn't get approved for the Ambassador to the U.N. years ago, couldn’t get approved for anything since, "begged" me for a non Senate approved job, which I gave him despite many saying "Don’t do it, sir," takes the job, mistakenly says "Libyan Model" on T.V., and..
— Donald J. Trump (@realDonaldTrump) January 29, 2020
....many more mistakes of judgement, gets fired because frankly, if I listened to him, we would be in World War Six by now, and goes out and IMMEDIATELY writes a nasty & untrue book. All Classified National Security. Who would do this?
— Donald J. Trump (@realDonaldTrump) January 29, 2020
