The White House blasted the impeachment inquiry into Donald Trump as "completely baseless" Friday, signalling it would not seek to defend the president in Democratic-led hearings to draw up formal charges against him.

But Republicans demanded that Joe Biden's son Hunter, the lawmaker leading the impeachment probe Adam Schiff, and the whistleblower at the origin of the inquiry all testify next week before the House Judiciary Committee.

"As you know, your impeachment inquiry is completely baseless and has violated basic principles of due process and fundamental fairness," White House chief lawyer Pat Cipollone wrote in a letter to the committee chair, Jerry Nadler.

"House Democrats have wasted enough of America's time with this charade. You should end this inquiry now and not waste even more time with additional hearings," he wrote.

Cipollone issued the letter minutes before a deadline to declare whether the White House would deploy representatives to defend Trump against accusations he abused his office by pressuring Ukraine to find dirt on former vice president Biden, his potential challenger in the 2020 election.

Nadler's committee is to meet starting Monday to review the evidence from investigators and decide whether to charge Trump with abuse of power, bribery and obstruction.

Those charges could become articles of impeachment sent to the full House to vote on within weeks.

If they pass the Democratic-led House as expected, it would make Trump only the third president in US history to be impeached.

That would set up a trial next month in the Republican-controlled Senate, seen as likely to acquit him.

Copyright Agence France-Presse, 2019