US President Donald Trump (L), John Bolton (R). Photograph:( Reuters )
His testimony will likely be damning for Trump as he will be his closest aide to testify if he appears before the senate
As Donald Trump's impeachment continues in the Senate, his former national security adviser John Bolton has confirmed in his new book that Trump had withheld military aid to Ukraine to force the country into probing his rival Joe Biden and his son Hunter Biden.
According to an unpublished manuscript of Bolton's book accessed by the New York Times, Trump called for a month-long hold on a three-hundred-and-ninety-one million dollars aid to Ukraine which is embroiled in a conflict with Russia.
Trump allegedly wanted the Ukrainian government to open investigations into the Bidens.
Watch: Trump had Ukraine aid withheld, Reveals Bolton's new book
Hunter Biden had served on the board of a Ukrainian energy firm while his father was the US vice-president under ex-president Obama.
The leaked manuscript comes at a time when Democrats are criticising Bolton for refusing to voluntarily testify in the Senate.
The former national security adviser is among the most sought after and high profile witnesses in the Trump trial.
While Bolton himself refused to testify, other national security council members have confirmed that he was concerned with the Ukraine scandal.
Bolton has said that he will testify in Senate only if he is subpoenaed.
Meanwhile, Trump has rejected Bolton's admission saying that his former aide is spreading lies to "sell" his book.
I NEVER told John Bolton that the aid to Ukraine was tied to investigations into Democrats, including the Bidens. In fact, he never complained about this at the time of his very public termination. If John Bolton said this, it was only to sell a book. With that being said, the...— Donald J. Trump (@realDonaldTrump) January 27, 2020
The former security adviser's admission comes a day after video from 2018 showed Trump interacting with his donors about Ukraine.
The US president was heard telling Lev Parnas and Igor Fruman that he wanted the American envoy to the Ukraine Mary Yovanovich fired.
John Bolton had served as US national security adviser for over a year and was among highest-ranking officials to express concerns over Ukraine.
His testimony will likely be damning for Trump as he will be his closest aide to testify if he appears before the Senate.