Queen Elizabeth, 95, has tested positive for COVID and is experiencing mild symptoms, Buckingham Palace said on Sunday.
"The queen has today tested positive for COVID," the Palace said. "Her Majesty is experiencing mild cold like symptoms but expects to continue light duties at Windsor over the coming week.
"She will continue to receive medical attention and will follow all appropriate guidelines."
Charles, 73, the heir to the throne, earlier this month pulled out of an event after contracting coronavirus for a second time. A palace source said he had met the queen just days before.
The health of the queen, the world's oldest and longest-reigning monarch, has been in the spotlight since she spent a night in hospital last October for an unspecified ailment and then was advised by her doctors to rest.
Elizabeth on Wednesday quipped to members of the royal household that she could not move much as she carried out her first in-person engagement since Charles tested positive.
Fourteen countries including Britain, Canada, and Germany have condemned the Israeli security cabinet's approval of 19 new settlements in the occupied West Bank on Wednesday, saying they violated international law and risked fuelling instability.
The US Justice Department has found more than a million more documents potentially tied to convicted American financier Jeffrey Epstein, delaying a full release for weeks while officials redact details to protect victims, the Department of Justice said on Wednesday.
Russia plans to put a nuclear power plant on the moon in the next decade to supply its lunar space programme and a joint Russian-Chinese research station, as major powers rush to explore the earth's only natural satellite.
An earthquake with a magnitude of 6.1 struck Taiwan's southeastern coastal county of Taitung on Wednesday, the island's weather administration said, although there were no immediate reports of damage.