US President Joe Biden has tested negative for Covid-19 in the wake of his chief spokeswoman testing positive, the White House said Monday.

The "president was tested as well, a PCR test yesterday, and he tested negative," Principal Deputy Press Secretary Karine Jean-Pierre told reporters aboard Air Force One, on the way to the UN climate summit in Glasgow.

Jean-Pierre said Biden's test on Sunday was not in response to news of the positive result for Press Secretary Jen Psaki, but was done "independently" and was "required for entering the UK."

Psaki, who has frequent access to Biden in the White House, pulled out of his trip to Rome for a G20 summit and the following Glasgow event after family members tested positive for Covid-19.

On Sunday she said that after testing negative all week, she had just had a positive result.

However, she said she had not had "close contact" with Biden or other senior White House staff since her family's first positive results.

Biden, 78, has been vaccinated and also received a booster shot.