Trump: It's a foregone conclusion House will vote to impeach me

Democrats are pushing to impeach the president, with key US diplomats due to testify to House investigators this week.

Donald Trump says it is a foregone conclusion the Democrat-led House of Representatives will vote to impeach him over his request to Ukraine to investigate Joe Biden and his son.

The Republican president made the comments at a Cabinet meeting as his opponents attempt to build public support for the impeachment inquiry, despite Mr Trump's administration refusing to help them.

Democrats, who have a majority in the House, are pushing for Mr Trump to be impeached for asking Ukraine president Volodomyr Zelenskiy to look into 2020 presidential hopeful Joe Biden and his son, Hunter, who was on the board of a Ukrainian oil company.

If the House approves articles of impeachment the upper Congress chamber, known as the Senate, would have to look into whether to remove Mr Trump from office.

The president's fellow Republicans have a majority in the Senate and they are not keen on removing Mr Trump, although leading Republican Mitt Romney has criticised him.

Mr Trump, who is accused of abusing his office by trying to get a foreign power to interfere in the 2020 US election, replied "yes" when asked if it was a foregone conclusion that House Democrats will vote to impeach him.

He added that if they do not he will get re-elected next year.

The president said Republicans need to stick together to fight the impeachment inquiry, adding that Democrats are also standing firm.

Michael Duffey, national security programmes associate director at the Office of Management and Budget, was scheduled to testify behind closed doors on Wednesday over Mr Trump's decision to withhold $391m (£301m) in security aid to Ukraine before asking its president to investigate the Bidens.

However, he and acting White House budget director Russell Vought said they would not provide depositions to the committees.

Other current and former administration officials have defied White House demands to not co-operate.

Bill Taylor, the top US diplomat in Ukraine, is due to provide crucial testimony to House impeachment investigators on Tuesday based on Mr Trump withholding congressionally-approved US security aid to Ukraine to help Kiev deal with Russia-backed separatists.

Texts with US ambassador to the EU Gordon Sondland have surfaced, with Mr Taylor saying: "I think it's crazy to withhold security assistance for help with a political campaign."

Mr Sondland, saying there was no favour for a favour, responded: "The president has been crystal clear no quid pro quos of any kind."

In written testimony last week, Mr Sondland said Mr Trump in May told senior US officials to deal directly with his personal lawyer, Rudy Giuliani, about US policy on Ukraine - raising concern American foreign policy was being outsourced to a private citizen and for the president's personal political benefit.

House Democrats have released a fact sheet and video, using publicly available information about the Ukraine scandal, in an attempt to make their case for impeachment.

Democrats said the information shows Mr Trump "believes he is above the law" and that "House Republicans' complicity and silence only serves to keep him there".

The president has said he did nothing wrong and his call with Mr Zelenskiy was "perfect".

Also due to testify at the closed impeachment inquiry session on Wednesday is acting assistant secretary of state for Europe Philip Reeker.

Laura Cooper, the US deputy assistant secretary of defence for Russia, Ukraine and Eurasia, and Alexander Vindman, a Europe adviser on the National Security Council are due to testify on Thursday.