US in ‘constitutional crisis’

House Speaker Nancy Pelosi said the US is in a "constitutional crisis" triggered by President Donald Trump's refusal to comply with congressional inquiries into his actions, mainly in connection with the Russian election interference probe.

"Trump and his Administration's decision to ignore the oath of office has triggered a constitutional crisis," Pelosi, the country's most powerful Democratic politician, said on Twitter on Thursday.

Trump and the Democratic-controlled House of Representatives have been locked in a bitter standoff since the publication late last month of the partially redacted Mueller report on Russian interference in the 2016 election that brought Trump to office.

The report by Special Counsel Robert Mueller found no evidence that Trump criminally colluded with Russia, but Democrats have been hotly disputing Trump's assertion that it also exonerated him of trying to obstruct justice.

With substantial powers to run their own investigations, House Democrats have been demanding a full and unredacted copy of the Mueller report, as well as the president's tax returns.

Trump has ordered his officials in the Treasury and Justice departments not to comply, putting pressure on the Democrats to launch impeachment proceedings that would grant them greater powers, despite the reluctance of many to take such a divisive and politically fraught path.

The Democrats are instead using an obscure legal move known as "inherent contempt" to try to force Attorney General William Barr to release the full report.

Meanwhile, two House Democrats on Thursday joined activists at the US Capitol who presented Congress with signatures of 10 million people calling on lawmakers to begin impeachment proceedings against President Donald Trump.