Vladimir Putin intends to cut short his attendance at the Group of 20 summit in Brisbane on Sunday, a Russian source said, with the strongman facing intense pressure from the West over Ukraine.

"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."