The Democrats have announced two articles of impeachment against Donald Trump, charging him with abuse of power and obstruction of Congress.
The charges stem from the president’s pressure on Ukraine to announce investigations into his political rivals as he withheld aid to the country.
US House Judiciary Committee chief Jerry Nadler said: “We do not take this action lightly. But we have taken an oath to defend the Constitution.
“And unlike President Trump, we understand that our duty first and foremost is to protect the Constitution and to protect the interests of the American people.”
Earlier on Tuesday, Mr Trump tweeted that he has done “NOTHING” wrong and that impeaching a president with his record would be “sheer Political Madness!”
.@RepJerryNadler: "Today, in service to our duty to the Constitution and to our country, the House Committee on the Judiciary is introducing two Articles of Impeachment charging the President of the United States, Donald J. Trump, with committing high crimes and misdemeanors." pic.twitter.com/qn3XAlr4Ng
— CSPAN (@cspan) December 10, 2019
Mr Nadler said the Democrats had moved for impeachment now as the integrity of the 2020 election was at stake.
The articles will be put before the House of Representatives Judiciary Committee later this week for approval.
If they are passed, they then go to the lower chamber for a full vote.
Should they be approved by a simple majority in the House, controlled by the Democrats, Trump will be impeached and a trial will be held in the Republican-led Senate early next year.
For Trump to be removed as president, two-thirds (67%) of the Senate must vote to convict. Vice President Mike Pence then take over as commander-in-chief.
House of Representatives speaker Nancy Pelosi said ahead of the announcement that Mr Trump tried to “corrupt our upcoming elections” and remains a “threat to our democracy and national security”.
She said the House was taking next steps to “defend the democracy”.