WASHINGTON — Senate Majority Leader Mitch McConnell, R-Ky., on Tuesday said Senate Republicans are prepared to move forward on an impeachment trial of President Donald Trump without agreeing first to rules about witnesses and without any Democratic votes.

"We have the votes once the impeachment trial has begun to pass a resolution, essentially the same, very similar to the 100-to-nothing vote" in the impeachment trial of former President Bill Clinton, McConnell told reporters in the Capitol.

By relying only on votes from his 53-member caucus, McConnell effectively rejected the demands by House and Senate Democrats that any rules for a trial be negotiated and agreed upon before a trial began.

Democrats want procedures for a trial that would allow witnesses to be called, a prospect Republicans have so far shown little interest in.

Instead, McConnell said the rules would be modeled upon Clinton's impeachment trial, which allowed the trial to begin with opening arguments without first requiring the question of witnesses and documents to be settled. "What's good for President Clinton is good for President Trump."

McConnell described the first part of a trial as a "phase one," which he said would include "arguments from the prosecution, arguments from the defense, and then a period of written questions" from senators.

He did not, however, suggest what a timeline for a trial might look like.

House Speaker Nancy Pelosi, D-Calif., has so far refused to formally send the articles of impeachment passed by the House late last year over to the Senate, a crucial next step before the upper chamber can begin proceedings.

On Tuesday, McConnell acknowledged that, until Pelosi acts, the Senate is effectively frozen. "It's the rule of impeachment in the Senate that we must receive the papers [from the House]," he said, "and it continues to be my hope that the Speaker will send them on over."

The question of witnesses grew more pressing on Monday, when former National Security Advisor John Bolton said he would be willing to testify before the Senate if he were subpoenaed to do so.

Asked about Bolton's willingness to testify, Trump on Tuesday told reporters in the Oval Office that "it'll be up to the Senate" whether Bolton testifies. "He would know nothing about what we're talking about," Trump said.

But according to current and former national security officials, Bolton has broad, firsthand knowledge of Trump's interactions with Ukraine.

Fiona Hill, a former top Bolton aide, testified before the House late last year that Bolton was vehemently opposed to the plan to pressure Ukraine to launch investigations that would benefit Trump's reelection campaign.