Democrats have announced the House will vote on January 15 on sending articles of impeachment against President Donald Trump to the Senate.
House Speaker Nancy Pelosi told fellow Democrats she would also name the House managers who will prosecute the case against President Trump in the Senate trial.
Nancy Pelosi has been withholding the articles of impeachment in a row with Republicans over allowing witnesses.
Donald Trump was impeached by the Democratic-led House last month.
The president is accused of abuse of power and obstruction of Congress.
He denies trying to pressure Ukraine to open an investigation into his would-be Democratic White House challenger Joe Biden.
President Trump has been touting unsubstantiated corruption claims about Joe Biden and his son, Hunter, who accepted a lucrative board position with a Ukrainian energy company while his father handled American-Ukraine relations as US vice-president.
The impeachment trial by the Senate will be only the third ever of a US president.
Donald Trump’s fellow Republicans control the chamber 53-47, and are all but certain to acquit him.
Once the resolution is approved, the House managers will walk to the Senate and formally present the articles of impeachment in the well of the chamber, escorted by the sergeant-at-arms. The articles of impeachment will be read out.
On January 14, Senate leader Mitch McConnell met Republican senators behind closed doors to map out the ground rules.
He said the trial was likely to begin in earnest on January 21.
The first couple of days will involve housekeeping duties, possibly later this week.
Supreme Court Chief Justice John Roberts will be sworn in to preside, and he will administer an oath to all 100 senators to deliver “impartial justice” as jurors.
Lawmakers may hear opening arguments next week. The House managers will lay out their case against President Trump, and his legal team will respond.
The trial is expected to last up to five weeks, with the Senate taking only Sundays off.
President Trump suggested over the weekend that he might prefer simply dismissing the charges rather than giving legitimacy to the “hoax” case against him.
Moderate Republican senators Susan Collins of Maine and Mitt Romney of Utah have made clear they would oppose any such motion.
On January 14, the White House said the president is “not afraid of a fight” in his trial.
Deputy press secretary Hogan Gidley said President Trump was in fact eager for witnesses to testify that “this man did nothing wrong”.
One of the biggest sticking points between House Democrats and Senate Republicans has been whether testimony will be allowed during the trial.
Republican senators Lindsey Graham and Mike Rounds said on January 14 the Senate’s trial plan will guarantee votes on whether to call witnesses and hear new evidence.
It takes just 51 votes to approve rules or call witnesses, meaning four Republican senators would have to side with Democrats to insist on testimony.
The White House is understood to have identified several possible defectors in the Republican ranks, including Susan Collins and Mitt Romney.
The others are Senators Lisa Murkowski of Alaska, Cory Gardner of Colorado and Lamar Alexander of Tennessee, who is retiring this year.
Republicans say that if witnesses are allowed, they may try to subpoena Joe Biden and his son, and the unidentified government whistleblower whose complaint about President Trump sparked the whole impeachment inquiry.