President Trump listed no new arguments or requests but vented his frustrations with the impeachment process in a six-page letter to House Speaker Nancy Pelosi on Tuesday. In a letter filled with exclamation marks and Trumpian verbiage, he offered his take the day before he likely becomes only the third U.S. president in history to be impeached.

"It is time for you and the highly partisan Democrats in Congress to immediately cease this impeachment fantasy and get back to work for the American People," the president wrote. "While I have no expectation that you will do so, I write this letter to you for the purpose of history and to put my thoughts on a permanent and indelible record."

Read President Trump's letter to Pelosi

Mr. Trump insisted that he's being treated worse than the defendants in the Salem Witch Trials, which resulted in executions. He also accused Democrats, without evidence, of being guilty of what they are set to impeach him for.

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"You are the ones interfering in America's elections," Mr. Trump wrote. "You are the ones subverting America's Democracy. You are the ones Obstructing Justice. You are the ones bringing pain and suffering to our Republic for your own selfish personal, political, and partisan gain."

The president is accused of two things: abusing his power for withholding aid from Ukraine to pressure the country to announce investigations that would benefit his reelection campaign, and obstructing Congress by not complying with its subpoenas throughout the impeachment process.

Mr. Trump also reiterated false narratives and complaints about impeachment, which he called a "hoax," while seated in the Oval Office alongside Guatemalan President Jimmy Morales on Tuesday.

"We're not entitled to lawyers, we're not entitled to witnesses, we're not entitled to anything in the House," he said.

President Trump speaks during a meeting with Guatemalan President Jimmy Morales in the Oval Office of the White House on December 17, 2019. Evan Vucci / AP

The House invited Mr. Trump and his legal counsel to testify. They declined. It also heard testimony from several witnesses called by Republican members of Congress.

Once the impeachment process moves to the Senate, Mr. Trump said it'll be up to Majority Leader Mitch McConnell to decide whether to call witnesses. Asked whether it would be McConnell's decision, Mr. Trump told reporters, "Yeah, he can decide."

Mr. Trump has previously expressed interest in calling witnesses in the Senate, where he has said the trial will be "fair." But McConnell has said he wants a swift trial, and he and Senate Judiciary Chairman Lindsey Graham have both said they don't pretend to be impartial jurors.

Senate Democrats have called on McConnell to allow four witnesses to testify in the Senate trial: White House chief of staff Mick Mulvaney, former national security adviser John Bolton, senior Mulvaney adviser Robert Blair, and Office of Management and Budget official Michael Duffey. All four were subpoenaed to testify in the House impeachment inquiry but didn't appear after the White House claimed that Mr. Trump's senior advisers have "absolute immunity" from congressional subpoenas. A federal judge refuted that.

McConnell told Fox News on Tuesday that if the Democrats called witnesses, Republicans would have a list, too, including the anonymous whistleblower whose complaint helped to launch Mr. Trump's impeachment, and Hunter Biden, the son of former Vice President Joe Biden.

"It's time to vote and move on and get back to get back to the business the American people sent us all here to do," McConnell said.