WASHINGTON - US House of Representatives Speaker Nancy Pelosi has tested positive for COVID-19 and will quarantine, an aide announced on Thursday.

"After testing negative this week, Speaker Pelosi received a positive test result for COVID-19 and is currently asymptomatic," deputy chief of staff Drew Hammill tweeted, adding that she's "fully vaccinated and boosted".

Hammill also said Pelosi, 82, will quarantine consistent with federal health guidance.

A planned congressional delegation to Asia, led by Pelosi, "will be postponed to a later date," according to Hammill.