Former US National Security Adviser John Bolton has expressed his willingness to testify at the upcoming parliamentary trial of President Donald Trump if the Senate formally requests it.

Bolton expressed his willingness to testify in a statement published yesterday, and as a former top aide to the White House, and witnessed several events that prompted the House of Representatives to hold Trump accountable last December, he could provide new evidence of Trump's efforts to pressure Ukraine to open an investigation To damage the reputation of his potential Democratic rival in the upcoming presidential election, Joe Biden, former Vice President Barack Obama.

The Democratic opposition in Congress is very interested in what the former National Security Adviser might say about pressures that the White House may have exercised to compel Ukraine to open an investigation into Joe Biden's son, and in particular it is to disrupt US military aid to Kiev by about four hundred million dollars.

Other witnesses in the US House of Representatives accountability inquiry said that Bolton vehemently opposed the effort of Trump's personal attorney, Rudy Giuliani, to pressure Kiev outside normal diplomatic channels.

A witness confirmed that John Bolton referred to this as a "drug deal," while a Senate aide told Reuters that congressional investigators believed that the former security adviser opposed Trump's decision to delay Ukraine's military aid to Ukraine.

The US president denied that his administration pressured Kiev to open an investigation aimed at harming his potential rival in the upcoming elections.

But the House of Representatives has accused Trump of abuse of power and obstruction of Congress, and the House of Representatives has approved by a comfortable majority an accountability of the president to be the third president in US history to be subjected to this measure.

Democrats say they will not set the date for Trump's trial in the Senate before they get Republicans guarantees about the trial procedures that the US president is rushing to organize, and he assures that it will not ultimately lead to his removal.

It is noteworthy that Bolton resigned last September at the request of Trump because of their differences over a number of files, including Iran.