Rishi Sunak will use the G20 summit to “call out Putin’s regime” for the havoc it is wreaking on Ukraine and the global economy with its invasion.
The British prime minister will fly to Bali, Indonesia, on Sunday to join other leaders of the world’s biggest economies including US President Joe Biden, France’s Emmanuel Macron and China’s Xi Jinping.
Russian President Vladimir Putin, who has faced unanimous condemnation from western leaders over the war, will not be in Bali. Russia will be represented by Foreign Minister Sergey Lavrov.
The annual G20 leaders’ gatherings began in response to the 2008 financial crisis, establishing the summit as the main global forum for economic co-operation.
But Mr Sunak said this year’s meeting will not be “business as usual” as the world confronts the most significant economic challenges since then, caused or exacerbated by the actions of a G20 member state.
The first summit since Russia’s invasion of Ukraine began in February looks set to be dominated by the fallout from the conflict, which has driven up energy and food prices.
In a statement before his departure, Mr Sunak said: “Putin’s war has caused devastation around the world — destroying lives and plunging the international economy into turmoil.
“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 co-operation 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.”
Mr Sunak is expected to deliver a speech during the first plenary session on Tuesday when Mr Lavrov will attend.
Russia’s top diplomat walked out when challenged about the invasion at a G20 foreign ministers’ meeting in July.
Finding consensus on international issues is difficult for the Group of 20 major economies, as it encompasses geopolitical rivals such as the US and China.
With divisions deepened by the Ukraine war, there is uncertainty over whether leaders will be able to agree a traditional joint statement at the end of the summit.
The Indonesian hosts are understood to have scrapped the official family photo as some leaders will be reluctant to be pictured with Russia’s representative.
Weeks into the prime minister's job, the trip marks one of Mr Sunak’s first outings on the world stage after his flying visit to Egypt for the UN Cop27 climate talks a week ago.
He is expected to return to the UK on Thursday in time for the autumn budget, when Chancellor Jeremy Hunt could impose up to £60 billion in tax rises and spending cuts.