The US Senate has adopted ground rules for President Donald Trump's impeachment trial after nearly 13 hours of rancorous debate on the first day.Democratic prosecutors sparred with Mr Trump's lawyers over the process, while Republicans rejected their demands for more witnesses.
The trial will resume on Wednesday afternoon with arguments by the prosecution, to be followed by the defence and questions.
Senators have taken oaths to act as impartial jurors in a trial presided over by the US Chief Justice, John Roberts. House Democrats known as "impeachment managers" act as the prosecution, while Mr Trump's legal team acts as the defence.
Under the rules agreed on a first day of proceedings that finished close to 02:00 local time (07:00 GMT), each side will be given up to 24 hours to lay out their case in opening arguments, over three days.
After this finishes, probably early next week, senators will have a chance to ask questions. They have been given 16 hours.
Then attention will return again to the key issue of new witnesses and evidence.What happened?
Trump is the third US president to undergo an impeachment trial.
He is charged with abuse of power and obstructing the congressional inquiry. He denies wrongdoing.
Trump is being put on trial after being impeached last month by the Democratic-led House of Representatives.
But the Senate, which is controlled by his fellow Republicans, is not expected to convict and remove him from office.
At the World Economic Forum (WEF) in Davos, Switzerland, on Tuesday, Mr Trump dismissed the accusations against him as "just a hoax".