A 7-foot "nonscalable" fence is being erected around the perimeter of the U.S. Capitol complex less than 24-hours after rioters stormed into the building and disrupted the peaceful transfer of power, Army Secretary Ryan McCarthy said during a press conference Thursday. 

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The fence will remain around the complex for at least 30 days, which means it will be in place through the inauguration of President-elect Joe Biden on Jan. 20. 

Planning for the fence began Wednesday after droves of Trump supports descended on Washington while Congress counted electoral votes to confirm Biden’s win.

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Trump has falsely said there was widespread fraud in the election to explain his defeat and encouraged his supporters to come to Washington. 

The riots resulted in four deaths -- including a woman who had been shot -- as well as dozens of arrests, according to police. 

Workers install a fence in front of the U.S. Capitol on Jan. 7, 2021. (Reuters/Stephanie Keith)

Workers install a fence in front of the U.S. Capitol on Jan. 7, 2021. (Reuters/Stephanie Keith)

In addition to the fence, McCarthy said about 6,200 National Guard will also be available through Biden's inauguration.

Roughly 850 troops are slated to be in place on Capitol Hill Thursday with 90 others placed at 30 traffic locations across the city.

Additionally, D.C. Mayor Muriel Bowser extended a public emergency, which was declared Wednesday, for 15 days, allowing her to enact a curfew at any time. 

"Today’s events and the reasonable apprehension of an ongoing public emergency represent an immediate threat to the health, safety, and welfare of district residents that requires emergency protective actions," Bowser said Wednesday. 

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Prior to Wednesday, the nation’s capital had prepared for the possibility of violence by mobilizing the National Guard ahead of planned protests by Trump’s supporters in connection with the congressional vote.

Bowser has requested the limited National Guard deployment to help bolster the Metropolitan Police Department and even asked area residents to stay away from downtown D.C., and avoid confrontations with anyone who is "looking for a fight."

She warned: "We will not allow people to incite violence, intimidate our residents or cause destruction in our city."

The Associated Press and FOX News' Jennifer Griffin contributed to this report.