President Trump claimed Monday that White House Coronavirus Task Force coordinator Dr. Deborah Birx, who told CNN on Sunday that the pandemic is now "different" than it was before and "extraordinarily widespread," was caving to pressure from House Speaker Nancy Pelosi, who had harsh words for Birx.

Trump has insisted that the rising number of COVID-19 cases is merely the result of increased testing and not an indication that the spread of the disease has gotten worse, but Birx said that the country was in a "new phase" of the pandemic.

PELOSI ANNOUNCES SHE HAS 'NO CONFIDENCE' IN TOP WHITE HOUSE CORONAVIRUS ADVISER DEBORAH BIRX

"So Crazy Nancy Pelosi said horrible things about Dr. Deborah Birx, going after her because she was too positive on the very good job we are doing on combatting the China Virus, including Vaccines & Therapeutics. In order to counter Nancy, Deborah took the bait & hit us. Pathetic!"

Pelosi was critical of Birx and the rest of the administration in an interview with ABC News' Martha Raddatz.

WATCH: BIRX DEFENDS ADMINISTRATION'S CORONAVIRUS TESTING

"I think the president is spending -- spreading disinformation about the virus and she is his -- she is his appointee," Pelosi said. "So, I don't have confidence there, no."

When told of this during a CNN interview, Birx said she had "tremendous respect" for Pelosi, and then criticized a New York Times article that accused her of having an overly optimistic attitude toward the pandemic. Birx said that while she had said that there has been an improvement in the New York metropolitan area, there were new outbreaks in Houston, Baltimore, New Haven, and Washington, D.C., as well as "ongoing cases" in Boston and Chicago.

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"This was not a pollyannish view," Birx went on. "I’ve never been called pollyannish, or non-scientific, or non-data driven. I will stake my 40-year career on those fundamental principles of using data to implement better programs and save lives."

Fox News' Gregg Re contributed to this report.