WASHINGTON (AP) — Homeland Security Secretary Alejandro Mayorkas tested positive Tuesday for COVID-19 and is isolating at home, the agency said. 

The secretary has been fully vaccinated and is experiencing only "mild congestion," DHS said in a statement. 

The agency said he will work from home under the protocols recommended by the U.S. Centers for Disease and Prevention. 

DHS said contract tracing is being done to check for possible exposure among others. 

Mayorkas was with President Joe Biden Saturday at the annual National Peace Officers' Memorial Service at the Capitol, standing on the podium between first lady Jill Biden and FBI Director Christopher Wray. 

The positive test requires him to cancel a scheduled trip this week to Colombia, where he was going to join Secretary of State Antony Blinken for discussions in part centered on efforts to address what officials are calling an unprecedented flow of migrants, particularly from Venezuela and Haiti, throughout the hemisphere.

DHS, the third-largest Cabinet agency, oversees the nation's primary immigration enforcement agencies, among other responsibilities.