President Biden faced criticism for removing his face mask while visiting the Lincoln Memorial on Wednesday night hours after signing an executive order requiring masks on federal property to prevent the spread of coronavirus.

"Wearing masks isn't a partisan issue – it's a patriotic act that can save countless lives. That's why I signed an executive order today issuing a mask mandate on federal property. It's time to mask up, America," Biden wrote on Twitter on Wednesday night.

Conservatives were quick to call Biden out.

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"Does Joe Biden's new executive order mandating masks on federal property not apply to Joe Biden while he's on federal property? Because here he is at the Lincoln Memorial with no mask just hours after signing it," Turning Point USA's Charlie Kirk wrote on Twitter.

"Biden signed a mask mandate requiring everyone who is on federal land to have to wear masks. Here is Biden tonight at the Lincoln Memorial, which is on federal land, not wearing a mask," The Daily Wire's Ryan Saavedra wrote on Twitter.

Biden's executive order, the "100-day masking challenge," will require masks and social distancing in all federal buildings, on all federal land and by federal employees and contractors, and on airlines, trains and transit systems traveling between states. 

While a president cannot tell state and local officials what to require, Biden’s order will urge states to enact their own mandates. Most states have already done so. 

President Joe Biden addresses the nation at the Celebrating America concert at the Lincoln Memorial in Washington, Wednesday, Jan. 20, 2021, after his inauguration.. (Joshua Roberts/Pool photo via AP)

During his inaugural address, the new commander in chief warned that the nation's "darkest and most deadly" coronavirus pandemic days could be ahead of it.

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Fox News' inquiry to the White House was not immediately returned.

Fox News' Morgan Phillips contributed to this report.