US President Donald Trump and his lawyers will not take part in a congressional impeachment hearing this week, the White House has said.

Key points: Mr Trump won't attend hearings unless the process is changed

Mr Trump won't attend hearings unless the process is changed His lawyer says the process lacks "fundamental fairness"

His lawyer says the process lacks "fundamental fairness" The White House has been given a new deadline of Friday to say whether Mr Trump will mount a defence

Mr Trump's aides responded defiantly to the first of two crucial deadlines he faces in Congress this week, as Democrats prepare to shift the focus of their impeachment inquiry from fact-finding to the consideration of possible charges of misconduct over his dealings with Ukraine.

The Democratic-led House of Representatives Judiciary Committee, tasked with considering charges known as articles of impeachment, had given Mr Trump until Sunday evening to say whether he would dispatch a lawyer to take part in the judiciary panel's proceedings on Wednesday.

"We cannot fairly be expected to participate in a hearing while the witnesses are yet to be named and while it remains unclear whether the Judiciary Committee will afford the President a fair process through additional hearings," White House counsel Pat Cipollone wrote to Judiciary Committee Chairman Jerrold Nadler, according to a copy of a letter seen by Reuters.

Mr Cipollone said there had been a "complete lack of due process and fundamental fairness afforded the President".

He did not rule out participation in further proceedings, but signalled that the Democrats would first have to make major procedural concessions.

Mr Nadler has given the White House a Friday deadline to say whether Mr Trump will mount a defence in broader impeachment proceedings.

The Judiciary Committee’s Democratic staff did not immediately reply to a request for comment on the White House's refusal to participate in the hearing, which would have been the first direct involvement by the Trump camp in a process he has condemned as a partisan "witch hunt".

"Not one process complaint made by the President and his Republican allies in Congress so far has turned out to be genuine," Democratic US Representative Don Beyer tweeted in response to the White House letter.

Congressional investigators have been looking into whether Mr Trump abused his power by pressuring Ukraine to launch investigations of former Democratic vice-president Joe Biden, who is running to unseat him in the 2020 presidential election, and a discredited conspiracy theory that Ukraine, not Russia, interfered in the 2016 US presidential election.

Reuters