US House Speaker Nancy Pelosi has announced a formal impeachment inquiry of President Donald Trump, alleging actions taken by the President to influence the US elections had "seriously violated the constitution".
"This week, the President admitted to asking the President of Ukraine to take actions which would benefit him politically," she told reporters in Washington on Wednesday.
"The actions of the Trump presidency revealed the dishonourable fact of the President's betrayal of his oath of Office, betrayal of our national security and betrayal of the integrity of our elections."
House Speaker Nancy Pelosi reads a statement announcing a formal impeachment inquiry into US President Donald Trump. Source: AP
The decision was made to launch formal proceedings after a growing scandal involving a phone call between Mr Trump and the Ukrainian President, in which he allegedly urged Volodymyr Zelensky to launch a corruption probe into his presidential competitor Joe Biden, and his son, Hunter.
"The President must be held accountable. No-one is above the law," the top Democrat said.
"The law is unequivocal."
Ms Pelosi announced the inquiry after meeting with members of her party, where impeachment calls surged despite concerns by the Democratic leadership that such a move could hurt their chances in the 2020 White House battle.
The formal impeachment inquiry in the House of Representatives is the first step in a process that could ultimately lead to Mr Trump's removal from office. If this happens, Mr Trump would become the third President to be impeached in US history.
Following the announcement, Mr Trump slammed the inquiry as "witch hunt garbage" and "presidential harassment".
"They never even saw the transcript of the call. A total Witch Hunt," he tweeted on Wednesday.
'Impeachment 'to boost re-election chances'
Earlier on Tuesday, Mr Trump brushed off the expected announcement of an impeachment inquiry against him, saying such a move would only boost his re-election chances in 2020.
"If she does that, they all say that's a positive for me in the election," Mr Trump said on the sidelines of the United Nations General Assembly.
The impeachment inquiry centres on Mr Trump's reported attempt to pressure the incoming president of Ukraine to open a corruption investigation into his main challenger for the White House, Joe Biden, and Biden's son Hunter.
Triggering the confrontation was an as yet secret whistleblower complaint involving Mr Trump's phone call on July 25 with Ukrainian President Volodymyr Zelensky.
Mr Trump earlier announced he would release the transcript of the call, in which he allegedly tied aid to Kiev to the opening of a corruption probe into Mr Biden.
"I am currently at the United Nations representing our Country, but have authorised the release tomorrow of the complete, fully declassified and unredacted transcript of my phone conversation with President Zelensky of Ukraine," Mr Trump tweeted.
"You will see it was a very friendly and totally appropriate call. No pressure and, unlike Joe Biden and his son, NO quid pro quo!
"This is nothing more than a continuation of the Greatest and most Destructive Witch Hunt of all time!"
Mr Biden himself - a former vice president who had until now held off from calling impeachment - announced on Tuesday that he now supported the move unless the US President fully cooperates with congressional investigations into the Ukraine scandal and other controversies.
"We have a president who believes there is no limit to his power," Mr Biden told a news conference. "We have a president who believes he is above the law."
"If he continues to obstruct Congress and flaunt the law, Donald Trump leaves Congress in my view no choice but to initiate impeachment," Mr Biden said. "That would be a tragedy, but a tragedy of his own making."
The White House has refused to release to Congress the secret complaint from an intelligence community whistleblower.
