Germany insisted on Friday that any joint statement from the ongoing G20 finance ministers meeting must mention "war", following reports that host India wanted to avoid using the word.

Hosting a raft of Group of 20 meetings during its presidency this year puts India in an awkward position, as it has refused to condemn the invasion of Ukraine by its "time-tested friend" Russia.

Media reports said that India wanted to keep the word "war" out of any final statement from the meeting of G20 finance ministers and central bank heads that wraps up on Saturday in Bengaluru.

Russia is a member of the G20 but did not have a ministerial-level representative at the gathering. Next week, however, Sergei Lavrov is expected to attend a meeting of G20 foreign ministers in New Delhi.

"For a year we have been witnesses of this awful war in Ukraine started by Russia. And especially on a day like this, and at an occasion such as a G20 event, we need absolute clarity," German Finance Minister Christian Linder said, alluding to the one-year anniversary of the February 24 invasion.

"This is a war. And this war has a cause, has one cause, and that is Russia and (Russian President) Vladimir Putin. That must be expressed clearly at this G20 finance meeting," Lindner told a news conference.

He said it would be "unacceptable for Germany" if the language from a leaders' declaration at a G20 summit in Indonesia in November -- which Putin did not attend -- was weakened.

That declaration, issued in Bali, said that "most members strongly condemned the war".

"I have no doubt that the Indian presidency will also stick to the language of Bali," Lindner said.

"There can be, with Russia, no business as usual. There will be no business as usual with Russia in future as long as this brutal war is waged further."

It remains unclear whether the meeting in Bengaluru will yield any joint statement at all, as similar gatherings have failed to in the past.