The US Senate has rejected repeated Democratic attempts to secure new evidence in President Donald Trump’s impeachment as his trial began.
Senate Majority leader Mitch McConnell meanwhile backed off on a plan to fast-track the hearings after coming under pressure from fellow Republicans.
Democrats said this would have been no less than a cover-up.
Mr Trump is charged with abuse of power and obstructing the congressional inquiry. He denies wrongdoing.
At the World Economic Forum in Davos, Switzerland, on Tuesday, Mr Trump dismissed the accusations against him as “just a hoax”.
Senators have taken oaths to act as impartial jurors, hearing arguments for six hours a day, six days a week in a trial presided over by the US Chief Justice, John Roberts.
It is only the third time in US history that a president is facing an impeachment trial and it is unclear how long it will last.
Mr Trump was 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 the president and remove him from office.