DC National Guard stand outside the Capitol, Wednesday night, Jan. 6, 2021, after a day of rioting protesters. It's been a stunning day as a number of lawmakers and then the mob of protesters tried to overturn America's presidential election, undercut the nation's democracy and keep Democrat Joe Biden from replacing Trump in the White House. (John Minchillo/AP)

Thousands of National Guard troops from surrounding states will deploy to Washington, D.C., by the weekend to bolster defenses around the national capital after a mob of President Donald Trump’s supporters on Wednesday forced their way into the U.S. Capitol, the Army’s top civilian said Thursday.

Army Secretary Ryan McCarthy said more than 5,000 troops from six states will join the 1,100 D.C. Nation Guard members already on duty in Washington to man checkpoints around the city, including positions around the Capitol. McCarthy, in a phone call Thursday with reporters, called “horrible and shameful” the siege one day earlier of the Capitol Building by angry Trump backers. Some attacked police, broke into the Capitol and delayed a vote by lawmakers to certify President-elect Joe Biden’s victory.

National Guard troops from Virginia, Maryland, New Jersey, Delaware, Pennsylvania and New York will deploy to D.C. in the coming days, McCarthy said. The Army secretary said they would remain in the city, working 12-hour shifts, for as many as 30 days, but at least through the Jan. 20 inauguration of Biden.

“We are singularly focused on putting a plan in place to ensure that we have the adequate level of capability to support this next really extraordinary milestone of the transfer of power on the 20th of January,” McCarthy said. “We're keenly focused on that.”

In a statement Thursday, Acting Defense Secretary Christopher Miller condemned Wednesday’s assault on the Capitol and committed to doing his part to ensure the peaceful transfer of power to Biden’s administration later this month. He praised the National Guard for helping secure the Capitol on Wednesday night, allowing Congress to complete its early Thursday morning certification of Biden’s victory.

“Our Republic may have been disrupted yesterday, but the resolve of our legislators to conduct the people’s business did not waver,” Miller said. “Due to their efforts, supported by local and federal law enforcement and the National Guard, the attempts of those who tried to stop our government from functioning failed.”

The entire D.C. National Guard was activated Wednesday amid the riot. Some were deployed to the Capitol in riot gear to help local and federal law enforcement secure the building. National Guard troops deployed so far have not been armed with firearms or non-lethal weapons. McCarthy said Thursday that Pentagon officials were considering changes to “the rules for the use of force,” which includes authorizations to carry weapons. He did not elaborate on potential changes to those rules.

McCarthy defended the National Guard’s response to the riot Wednesday, after lawmakers and other raised questions about how the president’s supporters were able to overrun security around the building. The Army secretary said the Pentagon had provided all the Guard forces that D.C. officials had requested before Wednesday. The troops’ response once the melee began was complicated by the need for D.C. or Capitol Hill police officials to formally request more troops or mission changes for Guard forces. Top Pentagon officials then had to approve those requests before troops could be moved, he said.

Trump supporters successfully delayed the congressional vote to certify Biden’s win, breaking through security and entering both chambers of Congress, forcing lawmakers to evacuate to secured locations throughout Capitol Hill. Ashli Babbitt -- a 35-year-old woman identified by news reports as an avid Trump supporter and Air Force veteran -- was shot to death by police during the incident, law enforcement officials said. Three other people died of medical emergencies during the incident, and more than 50 officers were injured, police said.

Congress reconvened after police secured the Capitol late Wednesday.

McCarthy said more than 100 D.C. National Guard troops were among those who helped secure the Capitol grounds. They were moved from traffic checkpoints around Washington to the D.C. National Guard Armory, where they were outfitted with riot gear and sent to Capitol Hill, he said.

“We were in position in less than two hours to go and help support the clearing of the Capitol,” McCarthy said. “Clearly the Capitol was under duress and if you're under duress, minutes and seconds count … I get it. But [Guard troops] were moving hard and fast.”

McCarthy said hundreds of troops would remain stationed around the Capitol Building through at least Jan. 20. He told reporters about 850 National Guard troops would be stationed on Capitol Hill by Thursday evening, where they had nearly completed positioning a 7-foot non-scalable fence around the complex.

On Monday, officials announced the Pentagon had approved the activation of about 340 D.C. National Guard troops to help local law enforcement with crowd and traffic control.

Miller said Wednesday that he agreed to activate D.C.’s entire Guard force after he and Army Gen. Mark Milley, the chairman of the Joint Chiefs of Staff, had separately spoken with Vice President Mike Pence, Senate Majority Leader Mitch McConnell, R-Ky., and House Speaker Nancy Pelosi, D-Calif. Those top U.S. officials were at the Capitol when the mob stormed the building.

“We are prepared to provide additional support as necessary and appropriate as requested by local authorities,” Miller said in a statement. “Our people are sworn to defend the Constitution and our democratic form of government, and they will act accordingly.”

The out-of-state deployments could grow larger in the coming days or be scaled back, a defense official said Thursday, calling the situation “still very, very fluid.”

In a statement announcing he would send 500 of his National Guard troops to Washington, New Jersey Gov. Phil Murphy said the forces were needed to “protect our democracy and facilitate the peaceful transition of power.”

“Our republic is built on the principles of democracy, peace, the right of the American people to freely choose their leaders,” Murphy said in a statement. “The brave men and women of our National Guard will be deployed in order to preserve those sacred principles.”

dickstein.corey@stripes.com Twitter: @CDicksteinDC