As the Trump administration stonewalls House Democrats' impeachment inquiry, with multiple witnesses being blocked from or refusing to testify, President Donald Trump on Monday morning asserted that "there is no reason" for Congress to receive testimony from anyone.

Trump's comments came after news broke that four White House officials who were scheduled to speak to House committees on Monday will not be appearing on Capitol Hill, and that allies of White House Chief of Staff Mick Mulvaney are reportedly forming a "firewall" against the inquiry.

"What I said on the phone call with the Ukrainian President is 'perfectly' stated," Trump tweeted, referring to the alleged quid pro quo at the center of the impeachment inquiry. "There is no reason to call witnesses to analyze my words and meaning."

Trump and his Republican allies are denying that the president committed an impeachable offense in July when he suggested in a phone call to Ukrainian President Volodymyr Zelensky that military aid would be withheld unless Ukraine opened an investigation into former Vice President Joe Biden.

The president called the phone call "perfect," but Lt. Col. Alexander Vindman of the National Security Council testified last week that key portions of the call were left out of the transcript that was released last month.

The Nation journalist John Nichols jokingly tweeted Monday that the president may have a point about the necessity, or lack thereof, of continuing to call witnesses to testify about the phone call of the president's conduct in the weeks since. A number of State Department officials have clearly laid out how the president and his allies sought to pressure Ukraine to help Trump in the 2020 election.

"In fairness to Trump, his words and meaning are more than sufficiently devastating to justify impeachment," Nichols tweeted.