The White House on Monday ordered everyone entering the west wing, where Donald Trump's daily operations are conducted, to wear masks after two aides tested positive for the coronavirus, government officials said.
The new guidelines, released in a memo to the President's team on Monday afternoon, reflect strict procedures at the highest levels of the U.S. government, due to fears that Trump and Vice President Mike Pence may be exposed to the virus.
Trump's military valet and Pence's press secretary tested positive for the coronavirus last week.
The 73-year-old said on Monday that he does not think these cases suggest that the White House system has broken.
"I didn't feel any vulnerability," said Trump, adding that he thought the situation was "well controlled".
Still, the president said he would discuss keeping some distance from Pence, perhaps communicating with him over the phone, for a period of time. Pence worked at the White House on Monday, but did not attend a press conference at Jardim de Rosas. Employees who attended wore masks and speakers used a podium other than that used by Trump.
Trump himself did not wear a mask while speaking and ended the briefing after a standoff with a reporter.
WATCH Trump abruptly ends the COVID-19 press conference:
ABC News first reported on the memo, which also said that unnecessary visits from other parts of the White House complex to the west wing area, which includes the Oval Office and workspace for senior advisers, are being discouraged.
Officials who work close to the president are being tested for coronavirus, but previously have not worn masks regularly.
"Common sense has finally prevailed," a senior government official told Reuters.
Trump hesitates to wear mask
Trump has been resistant to wearing a mask and has not put it on publicly, although he said he tried some behind the scenes during a visit to a mask factory in Arizona last week.
On Saturday, he met the top leaders of the US armed forces, the Chiefs of the Armed Forces and members of their national security team in the White House Office Room. Authorities did not wear masks, but they were tested for the virus in advance, a Pentagon spokesman said, adding that the social distance measures appear to have been enforced. Secret Service agents in the room wore masks.
The president is in the age group considered to be at high risk for complications from the coronavirus, which killed more than 80,000 people in the United States alone and devastated countries and economies worldwide.
Team members, including Jared Kushner, the president's senior adviser and son-in-law, wore masks on the White House property on Monday.
The White House said last week that it is stepping up precautions for people who spend time around Trump and Pence, who have resumed travel outside Washington. Both men are being tested for the virus daily.
"In addition to social detachment, daily temperature checks and symptom history, hand sanitizer and regular thorough cleaning of all workspaces, all employees close to the president and vice president are being tested daily for COVID-19, as well as guests, "White House spokesman Judd Deere said in a statement.
After Pence's press secretary Katie Miller tested positive for the virus last week, Trump was asked if people in the west wing would start wearing masks. He replied that people were already doing this. But he and his guests that day did not wear masks, and neither did the West Wing officials.
Miller is married to Stephen Miller, senior advisor to the White House and speechwriter to the president.
Some who had contact with Katie Miller were placed in partial quarantine. A government official said Pence worked at the White House on Monday, but would stay away from the president in the immediate future, in consultation with the White House medical unit.