The Russian prime minister, who is hosting the summit on tigers in St Petersburg, said the actor Leonardo DiCaprio had "literally tore his way through to Saint Petersburg," calling him "a real man" (or "muzhik") for his persistence, the Daily telegraph reported. He pledged $1 million to saving tigers.

DiCaprio was among the passengers on a Delta Airline jet that was forced to make an emergency landing in New York on Monday after losing an engine. His second plane faced strong headwinds and was required to make an unscheduled refuelling stop in Helsinki, Mr Putin told the audience.