President Donald Trump has hinted that he might be prepared to give evidence at the House impeachment inquiry following an invitation to do so from the chamber’s Speaker Nancy Pelosi.

Ms Pelosi issued the invitation ahead of a week when several key witnesses are expected to give evidence.

Mr Trump said in a tweet he “liked the idea” and would “strongly consider it”.

The president has often complained that the process is stacked against him, prompting Ms Pelosi to suggest the president should appear or answer questions in writing, if he chooses.

“If he has information that is exculpatory, that means ex, taking away, culpable, blame, then we look forward to seeing it,” she said in an interview that aired Sunday on CBS’s  Face The Nation.

Mr Trump “could come right before the committee and talk, speak all the truth that he wants if he wants”, she said.

On Monday, Mr Trump tweeted he might be willing to offer written evidence, saying: “She also said I could do it in writing.

Nancy Pelosi and Donald Trump (J. Scott Applewhite/Evan Vucci/AP)
Nancy Pelosi and Donald Trump (J. Scott Applewhite/Evan Vucci/AP)

“Even though I did nothing wrong, and don’t like giving credibility to this No Due Process Hoax, I like the idea & will, in order to get Congress focused again, strongly consider it!”

Senate Democratic leader Chuck Schumer said Mr Trump “should come to the committee and testify under oath.

“And he should allow all those around him to come to the committee and testify under oath,” Mr Schumer told reporters.

He said the White House’s insistence on blocking witnesses from cooperating begs the question: “What is he hiding?”

The comments come as the House Intelligence Committee prepares for a second week of public hearings as part of its inquiry, including with the man who is arguably the most important witness.

Election 2020 Nevada
Joe Biden (John Locher/AP)

Gordon Sondland, Mr Trump’s ambassador to the European Union, is among the only people interviewed to date who had direct conversations with the president about the situation because the White House has blocked others from cooperating with what it dismisses as a sham investigation.

And evidence suggests he was intimately involved in discussions that are at the heart of the investigation into whether Mr Trump held up US military aid to Ukraine to try to pressure the country’s president to announce an investigation into Democrats, including former Vice President Joe Biden, a leading 2020 candidate, and Mr Biden’s son Hunter.

Multiple witnesses overheard a phone call in which Mr Trump and Mr Sondland reportedly discussed efforts to push for the investigations.

In private evidence to impeachment investigators made public on Saturday, Tim Morrison, a former National Security Council aide and long-time Republican defence hawk, said Mr Sondland told him he was discussing Ukraine matters directly with Mr Trump.

Trump Impeachment
Gordon Sondland,(Pablo Martinez Monsivais/AP)

Mr Morrison said Mr Sondland and Mr Trump had spoken approximately five times between July 15 and September 11, the weeks that 391 million dollars in US assistance was withheld from Ukraine before it was released.

And he recounted that Mr Sondland told a top Ukrainian official in a meeting that the vital US military assistance might be freed up if the country’s top prosecutor “would go to the mike and announce that he was opening the Burisma investigation”.

Burisma is the company that hired Hunter Biden.

Mr Morrison’s evidence contradicted much of what Mr Sondland told congressional investigators during his own closed-door deposition, which the ambassador later amended.

Mr Trump has said he has no recollection of the overheard call and has suggested he barely knew Mr Sondland, a wealthy donor to his 2016 campaign.