"Today I am announcing the House of Representatives is moving forward with an official impeachment inquiry. I am directing our six committees to proceed with their investigations under that umbrella of an impeachment inquiry. The president must be held accountable. No one is above the law," Pelosi said.
According to sputnik, this came after US media reported last week that a government whistle-blower filed a complaint after Trump during a July phone call pressed Zelensky to investigate the son of former Vice President Joe Biden, Hunter Biden, for possible corruption, ahead of the 2020 US presidential election.
Pelosi's announcement did not go down well with Trump, who termed it a "total witch hunt" and "presidential harassment".
Training his guns at the Democrats, Trump said in a series of tweets, "Such an important day at the United Nations, so much work and so much success, and the Democrats purposely had to ruin and demean it with more breaking news Witch Hunt garbage. So bad for our Country! Pelosi, Nadler, Schiff and, of course, Maxine Waters! Can you believe this?"
"They never even saw the transcript of the call. A total Witch Hunt!" he said, before writing, "PRESIDENTIAL HARASSMENT!" in his last tweet.
Lawmakers have demanded that the Trump administration provide more information about the call. Earlier in the day, Trump, however, said he would release the full transcript of the phone call on Wednesday.
The reports have prompted fresh calls for Trump's impeachment, with many Democratic lawmakers denouncing the phone call as an attempt to get Ukraine to interfere in the upcoming US Presidential election, in which Biden is widely recognised as a top contender for the Democratic nomination.