A top adviser to President Donald Trump Donald John TrumpHR McMaster says president's policy to withdraw troops from Afghanistan is 'unwise' Cast of 'Parks and Rec' reunite for virtual town hall to address Wisconsin voters Biden says Trump should step down over coronavirus response MORE on Sunday said White House press secretary Sean Spicer provided “alternative facts” to reporters during his first briefing.

“You’re saying it’s a falsehood. And they’re giving, Sean Spicer, our press secretary, gave alternative facts to that,” Conway said on NBC’s “Meet the Press.”

Host Chuck Todd fired back at Conway over her comments.

ADVERTISEMENT

“Look, alternative facts are not facts,” said Chuck Todd. "They're falsehoods."

Spicer on Saturday conducted his first press briefing with reporters, railing against the media for its coverage of the crowd size at Trump's inauguration ceremony.

"This was the largest audience to ever witness an inauguration, period, both in person and around the globe,” Spicer said.

Photos and video from Friday’s ceremony showed fewer people in attendance for Trump’s ceremony compared to former President Barack Obama Barack Hussein ObamaThe Hill's 12:30 Report - Presented by Facebook - Don't expect a government check anytime soon Trump appointees stymie recommendations to boost minority voting: report Obama's first presidential memoir, 'A Promised Land,' set for November release MORE’s 2009 inauguration.

Trump also spoke of the crowd sizes on Saturday while speaking at CIA headquarters in Langley, Va.

Todd on Sunday said telling falsehoods “undermines the credibility” of the White House press shop.

But Conway argued it isn’t possible to know the size of Trump’s crowd during the inauguration ceremony.

“There’s no way to really quantify crowds. We all know that,” Conway said.

--This report was updated at 10:56 a.m.