WASHINGTON – House Speaker Nancy Pelosi said Thursday she would send the articles of impeachment against President Donald Trump to the Senate "soon."

The Republican-led Senate awaits the articles so it can begin a trial on whether to remove Trump from office. Removal would require a two-thirds vote of the senators.

But Pelosi has delayed sending the articles, which accuse Trump of abuse of power and obstruction of Congress, since the House approved them Dec. 18. She said she wants to know more about how the Senate would conduct its trial before naming the lawmakers to serve as managers. Pelosi reiterated this condition Thursday.

“No, I’m not holding them indefinitely," said Pelosi, D-Calif. "I’ll send them over when I’m ready. That will probably be soon."

The delay has tested the patience of some Senate Democrats, who began urging Pelosi to send the articles.

“I think if we’re going to do it, we should do it,” said Sen. Dianne Feinstein of California, the top Democrat on the Senate Judiciary Committee.

“We want to see what they’re willing to do and the manner in which they’ll do it," Pelosi said. “They don’t want documents, the documentation. They don’t want witnesses. They may want a dismissal, which is proof that they cannot – cannot – clear the president of wrongdoing."

Part of the impasse has focused on whether the Senate would hear from witnesses who didn't testify in the House inquiry. But Senate Majority Leader Mitch McConnell, R-Ky., said Tuesday that no decision would be made on witnesses until after opening statements from House managers and White House defense lawyers, and the submission of written questions from senators.

McConnell quoted Feinstein's concerns on the Senate floor Thursday and said Trump deserved a chance to clear his name.

"If it's serious and urgent, send them over," McConnell said, quoting Feinstein. "If it isn't, don't."

Sen. Lindsey Graham, R-S.C., introduced a resolution Thursday urging Pelosi to transmit the articles immediately and calling the delay a “gross infringement on the constitutional authority of the Senate to try impeachment.”

"What the Speaker has been doing is inconsistent with the Constitution and unfair to the president and the American people," Graham said.

While Republicans blasted the delay as a political game, Democrats said it allowed time for former national security adviser John Bolton, who declined an invitation to testify in the House, to announce Monday he would testify in the Senate trial if subpoenaed.

Senate Minority Leader Chuck Schumer, D-N.Y., has called for four witnesses, including acting White House chief of staff Mick Mulvaney.

The House accused Trump of abusing the power of his office by asking Ukraine President Volodymyr Zelensky to investigate his political rival, former Vice President Joe Biden, withholding a White House meeting and $391 million in military aid. The House also accused Trump of obstructing Congress by directing aides and agencies to defy subpoenas for documents and testimony, although some officials did testify.

Trump and congressional Republicans have argued he had the authority to set foreign policy and was justified in fighting corruption in Ukraine. Trump has said he expects to be exonerated in the Senate trial.

Contributing: Christal Hayes