The mayor of the US metropolis of Los Angeles, Eric Garcetti, tested positive for the corona virus during his participation in the UN world climate conference COP26 in Glasgow, Scotland.

"He feels good and is in his hotel room for self-isolation," said a message from his office on Twitter on Wednesday evening.

He is fully vaccinated.

Garcetti had attended a reception that morning with British Prime Minister Boris Johnson, Scotland's Prime Minister Nicola Sturgeon and about 40 other people.

A health expert expressed concern on Wednesday about the long queues at the summit.

"This is really worrying, I'm watching all of this very anxiously because I know how fragile the situation is," said researcher Devi Sridhar from the University of Edinburgh in a BBC interview.

At the UN World Climate Conference with more than 28,000 delegates, observers and journalists, there were very long queues at the entrance in the past few days.

The participants were partly led in a zigzag course to the security gates.

At times it took over an hour to get to the conference center, participants reported.

A negative corona rapid test must be presented daily at the entrance to the center.

Before the COP26, the host had also recommended a full vaccination.