The source added that the meeting would focus on the state of the global economy, the consequences of the war in Ukraine, and COVID-19 vaccines and pandemic preparedness.

Germany, along with its closest allies, would condemn Russia's invasion of Ukraine as the reason for the global economic slowdown, soaring prices on energy markets and possible famines, said the source.

"We will not leave the lies and propaganda of the Russian side uncommented," the source said during a call with journalists on Tuesday.

Western nations are preparing to stage coordinated walk-outs and other diplomatic snubs to protest against Russia's invasion of Ukraine at Wednesday's meeting of G20 finance ministers in Washington, their officials said.

While some in Western capitals argue that Russia's actions should mean it is excluded from global meetings altogether, that is not a view shared by others in the Group of 20 big economies, including notably China and Indonesia, which is chairing the group this year.

Moscow confirmed on Tuesday Finance Minister Anton Siluanov would lead Russia's delegation at the talks despite repeated protestations by Western diplomats that they could not go ahead as usual during a war in which thousands of civilians have died in bombardments by Russian troops.

British finance minister Rishi Sunak also will not attend certain G20 sessions, a British government source told Reuters.

And a French finance ministry official meanwhile expected some ministers from Group of Seven nations to leave their seats when their Russian peer was due to speak.

The divisions widened by the Ukraine war raise questions over the G20's future as the world's premier economic policy forum.

Conceived as a platform for the biggest wealthy and developing economies to cooperate on recovery efforts during the 2008-2009 global financial crisis, the G20 has since broached everything from global tax reform to pandemic debt relief and the fight against climate change, with a patchy record of success.

"The G20 is at risk of unraveling and this week is incredibly important," said Josh Lipsky, director of the Atlantic Council's GeoEconomics Center and a former IMF adviser.

Should Western democracies allow the group to wither in favor of the G7 or other groupings, it would cede significant economic influence to China, Lipsky said.

"Russia can align with China and I think that's a good outcome from Russia's perspective and actually gives them more influence than they have in a body like the G20," he said.

Both the French and the German official said there would be no agreed communique at the end of a meeting which had been originally due to discuss the state of the global economy and coordinating vaccine and other pandemic efforts.

Apart from the G7 nations - the United States, Canada, Japan, Britain, France, Germany and Italy - the G20 also incorporates emerging economies including China, India and Brazil that have starkly different views on how the global economy should work.