Senate Majority Leader Mitch McConnell of Ky., speaks with reporters after walking off the Senate floor on Capitol Hill in Washington. Picture: Patrick Semansky/AP

Palm Beach, Florida — The fate of a Senate impeachment trial for President Donald Trump is at an impasse as Republican and Democratic leaders remained at odds over what form it would take and what witnesses would be called.

Senate Majority Leader Mitch McConnell said he has not ruled out calling witnesses but also indicated that he was in no hurry to seek new testimony either. The Senate’s top Democrat, Chuck Schumer of New York, responded that any trial without witnesses would be “Kafkaesque” and a “sham.” He said he remained open to negotiating with McConnell, a Kentucky Republican.

“Let’s put it like this: If there are no documents and no witnesses, it will be very hard to come to an agreement,” Schumer told The Associated Press on Monday.

The House voted Wednesday to impeach Trump, who became only the third president in U.S. history to be formally charged with “high crimes and misdemeanors.” But the Senate trial may be held up until lawmakers can agree on how to proceed. Schumer is demanding witnesses who refused to appear during House committee hearings, including acting White House chief of staff Mick Mulvaney and former national security adviser John Bolton.

Marc Short, chief of staff to Vice President Mike Pence, speaks with members of the media outside the White House in Washington. Picture: Patrick Semansky/AP

McConnell, who has all but promised a swift acquittal of the president, has resisted making any guarantees, and has cautioned Trump against seeking the testimony of witnesses for fear of prolonging the trial. Instead, McConnell appears to have secured Republican support for his plans to impose a framework drawn from the 1999 impeachment trial of President Bill Clinton.

“We haven’t ruled out witnesses,” McConnell said Monday in an interview with “Fox and Friends.” “We’ve said let’s handle this case just like we did with President Clinton. Fair is fair.”

That trial featured a 100-0 vote on arrangements that established two weeks of presentations and argument before a partisan tally in which Republicans, who held the majority, called a limited number of witnesses. But Democrats now would need Republican votes to secure witness testimony — and Republicans believe they have the votes to eventually block those requests.