Biden's national security adviser tests positive for COVID

The US government says national security adviser Jake Sullivan has tested positive for COVID-19.

Sullivan is reportedly showing no symptoms and had not been in close contact with President Joe Biden.

He met in person with China's top diplomat Yang Jiechi in Luxembourg for four-and-a-half hours on Monday.

Among senior members of the Biden administration, Vice President Kamala Harris tested positive in April, and Secretary of State Antony Blinken tested positive last month.