Putin to leave G20 summit early: Russian delegate

"The programme of the second day (for Putin) is changing, it's being cut short," a source in the Russian delegation told AFP on condition of anonymity.

Putin will attend summit sessions on Sunday but will skip an official lunch and address reporters earlier than planned, the source said, adding: "Lunch is more of an entertainment."

The source denied that Putin was bowing out under pressure from top Western leaders, who accused him of "bullying" ex-Soviet Ukraine.

"There were no scandals," the source said.

But the Kremlin, mindful that Putin's exit might further stoke tensions, quickly moved to quash speculation that the Russian strongman was leaving early.

"The G20 summit will be over tomorrow, Putin will certainly leave it, when all the work is completed the president will leave," Putin's spokesman Dmitry Peskov said on Russian radio.

He denied that pressure from Western leaders, who have threatened Russia with more sanctions if fighting in eastern Ukraine intensifies, forced Putin to change plans.

"Sanctions are being actively and broadly discussed at all bilateral meetings but no one is putting pressure," Peskov said.

"This is complete nonsense," he told Russian reporters separately. "This is a usual, routine situation."

Putin is facing huge pressure from top Western leaders over Russia's support for a separatist insurgency in eastern Ukraine, with British Prime Minister David Cameron accusing Russia of "bullying a smaller state in Europe."

During a closed-door meeting between Cameron and Putin earlier Saturday, the British prime minister had warned that the Russian strongman had a choice to make, according to a Downing Street source.

"The prime minister was clear at the start of the Ukraine discussions that we face a fork in the road, in terms of where we go next," the source said, quoted by British media.

"We can either see implementation of the Minsk agreement and what follows from that in terms of an improvement of relations," the source said, referring to peace accords.

"Or we can see things go in a very different way in terms of relations between Russian and the UK, Europe and the US."