Nancy Pelosi, speaker of the U.S. House of Representatives, announced a mandatory mask policy on Wednesday that requires all members and staff to wear face coverings in the chamber.

"Members and staff will be required to wear masks in the halls of the House," Pelosi said during remarks on the House floor, adding that lawmakers can temporarily take off their masks when speaking.

The California Democrat also said she has the authority to direct the House sergeant-at-arms to tell members to leave if they fail to adhere to the requirement.

The announcement came hours after Congressman Louie Gohmert, a Texas Republican, tested positive for the coronavirus, or COVID-19.

Gohmert, who has frequently refused to wear a mask, was scheduled to fly to Midland, Texas with U.S. President Donald Trump Wednesday morning but tested positive in a pre-screen at the White House.

However, the eight-term congressman blamed the result on wearing a mask.

"I can't help but think that if I hadn't been wearing a mask so much in the last 10 days or so, I really wonder if I would have gotten it," he said during an interview with a local TV station.

At least two House members have announced plans to self-quarantine due to contact with Gohmert.

U.S. Attorney General William Barr, who was seen walking alongside with Gohmert after a hearing at the House Judiciary Committee, tested negative for the virus on Wednesday, according to a spokesperson.

At least the 10th U.S. lawmaker known to have tested positive, Gohmert is among a group of conservative Republicans who have been walking around the Capitol without wearing a mask.

"Very frankly, too many Republicans have continued to act extraordinarily irresponsibly," House Majority Leader Steny Hoyer told reporters on a press call on Wednesday.

The U.S. Centers for Disease Control and Prevention has said "cloth face coverings are a critical tool in the fight against COVID-19 that could reduce the spread of the disease, particularly when used universally within communities."

Whether to wear a mask in public during the coronavirus pandemic, however, has become a divisive issue in the United States. Trump has not endorsed the practice until earlier this month.

More than 4.4 million people in the country have been infected with the virus, along with over 150,000 deaths, according to the latest tally from Johns Hopkins University.

A model from the University of Washington's Institute for Health Metrics and Evaluation has shown that near-universal wearing of cloth or homemade masks could prevent up to 28,030 deaths across the United States before Oct. 1.

Gohmert is the latest in a growing number of U.S. politicians who have contracted the disease.

The White House announced earlier this week that National Security Advisor Robert O'Brien has tested positive for the coronavirus.

Trump told reporters at the White House on Wednesday that he has not seen O'Brien "in a while."

The White House recently ended regular temperature checks for all those entering the White House complex, but those who will come into close contact with Trump are still given rapid tests, the kind of which Gohmert received Wednesday.

Last week, a cafeteria employee working in the Eisenhower Executive Office Building, which is close to the White House, tested positive for the coronavirus, as did a U.S. Marine assigned to Trump's helicopter squadron ahead of the president's planned trip to his golf club in Bedminster, New Jersey.

Previously, one of Trump's military valets and Vice President Mike Pence's press secretary tested positive for the virus.