"Secretary Mayorkas tested positive this morning for the COVID-19 virus after taking a test as part of routine pre-travel protocols," spokesperson Marsha Espinosa said in a statement. "Secretary Mayorkas is experiencing only mild congestion."
The spokesperson added that contact tracing is underway. Mayorkas plans to isolate and work from home in accordance with CDC protocols.
Mayorkas joined President Biden, first lady Jill Biden, FBI Director Christopher Wray and several other high-ranking officials at the annual National Police Officers' Memorial Service at the U.S. Capitol on Saturday.
During the outdoor event, Mayorkas stood within a few feet of the president. In addition to Mayorkas, President Biden is fully vaccinated against COVID and received a booster shot late last month.
According to a White House official, Mr. Biden and the first lady were not determined to be a close contact of Secretary Mayorkas, because the event occurred outdoors and was held more than 48 hours before he tested positive.
CBS News has reached out to the FBI to ask about additional precautions in the wake of Mayorkas' diagnosis.
Last Friday, Mayorkas attended the U.S. Customs and Border Protection Valor Memorial and Wreath Laying Ceremony at the Woodrow Wilson Plaza in Washington, D.C. to honor 23 federal law enforcement officers who lost their lives in the line of duty. That event also took place outdoors.
In July, Mayorkas worked from home after close contact with a DHS employee who later tested positive for the coronavirus. Mayorkas experienced no symptoms and tested negative for COVID-19 following his July exposure.
Mayorkas' latest quarantine follows the Biden administration's sweeping new vaccine mandates for federal workers, contractors and health care staff. Mr. Biden signed an executive order last month requiring government employees and contractors to be fully vaccinated by November 22.
The Department of Labor has also developed a rule requiring all employers with at least 100 employees to ensure their workforce is fully vaccinated or require unvaccinated workers to get a negative test at least once a week.
The secretary was previously slated to appear before the Senate Judiciary committee on Thursday. Later this week, Mayorkas planned to travel to Colombia alongside Secretary of State Antony Blinken.
Fin Gomez contributed reporting.
for more features.