Rishi Sunak sets off for G20 with pledge to "call out Putin's regime"

British Prime Minister Rishi Sunak has pledged to "call out Putin's regime" at this year's G20 over the Russia-Ukraine conflict as he leaves for Indonesia for the annual summit on Sunday.

The Group of 20 (G20) of the world's biggest economies will bring together world leaders, where Sunak is expected to hold his first meeting with Prime Minister Narendra Modi since taking charge as the UK's first Indian-origin Prime Minister last month.

India's presidency of the G20 will kick off following the Heads of State and Government Summit in Bali from December 1.

"(Vladimir) Putin's war has caused devastation around the world destroying lives and plunging the international economy into turmoil," said Sunak in a statement before setting off for Bali.

"This G20 summit will not be business as usual. We will call out Putin's regime, and lay bare their utter contempt for the kind of international cooperation and respect for sovereignty forums like the G20 represent. In clear contrast to Putin's disruption, the UK and our allies will work together to make meaningful progress solving the economic challenges we face and making lives better for our people," he said.

Sunak will confront Russian Foreign Minister Sergei Lavrov in a speech during the G20's first plenary session, when all members are expected to attend, on Tuesday.

According to reports, Downing Street had prepared for the summit assuming Russia's President would be there. But Moscow revealed last week he wouldn't be attending and that the Kremlin would be sending Russia's foreign minister, Sergei Lavrov, instead.

The annual gatherings were initially established in response to the 2008 financial crisis, cementing the summit as the main global forum for economic cooperation. The meeting next week will take place as the world faces another significant set of economic challenges since 2008 caused or exacerbated by the Russia-Ukraine conflict.

Talks are set to be dominated by the fallout of G20 member-state Russia's actions, which the western economies believe has unleashed chaos in the global economy and seen energy and food prices skyrocket.

Russia's top diplomat previously walked out of a meeting of G20 foreign ministers in July when challenged over Moscow's actions in Ukraine.

While the traditional group photograph referred to as the "family photo" of world leaders has been ruled out as most do not want to share the frame with Russia, divisions deepened by the Ukraine war mean it is unclear whether a traditional joint statement will be agreed at the end of the Bali summit.