Vice President Mike Pence and President Donald Trump's personal lawyer Rudy Giuliani have declared they will not cooperate with a US House of Representatives impeachment inquiry into Trump's efforts to pressure Ukraine to investigate a political rival.
The decision to defy Congress illustrates Trump's determination to stonewall the Democratic-led impeachment effort, which threatens to consume his presidency.
Giuliani could face contempt of Congress charges, as he had been subject to a subpoena. Pence has not been subpoenaed but has been warned that refusal to cooperate could be interpreted as evidence of obstruction.
Other US government officials have not been as reluctant to cooperate.
House Democrats are focusing on Trump's request to Ukrainian President Volodymyr Zelenskiy in a July 25 phone call to look into unsubstantiated allegations about Joe Biden, the former vice president and a leading contender to run against Trump in the 2020 US election.
Senior US diplomat, George Kent, gave closed door testimony on Tuesday, one of several officials who've complied with congressional subpoenas, despite being ordered by the White House and state Department not to appear.
Kent, who has spent much of his career fighting corruption in Ukraine and elsewhere, is the second career diplomat to testify as part of the probe.
On Monday, Fiona Hill, Trump's former Russia adviser, said she and her then-boss, former national security adviser John Bolton, were alarmed by efforts to force Ukraine to investigate Biden and other rivals.
Hill told House committee members that Bolton characterised Giuliani as "a hand grenade who is going to blow everybody up." A Bolton spokeswoman said he would have no comment on the testimony.
Giuliani had faced a Tuesday deadline to produce requested documents. His lawyer, Jon Sale, said the documents were protected by legal principles that protect attorney-client communications and presidential communications.
"This appears to be an unconstitutional, baseless, and illegitimate 'impeachment inquiry,'" Sale wrote, echoing language the White House used last week.
Pence's lawyer, Matthew E. Morgan, also cited the White House's response, saying the House had not voted to authorise the inquiry. Democratic leaders have said no vote is necessary.giulin
Australian Associated Press