The African Union looks set to become the newest member of the G20, officials said Friday, as the bloc's bid won backing from existing members gathered for a summit in India.

G20 host and Indian Prime Minister Narendra Modi has called for the pan-African organisation to become a permanent member, arguing developing nations need a greater say in global decision-making.

The proposal has won backing from Washington and on Friday the European Union said it would also back the move.

"I look forward to welcoming the AU as a permanent member of the G20", European Council president Charles Michel told reporters in New Delhi, where the two-day G20 summit begins on Saturday.

The Group of 20 major economies currently consists of 19 countries and the European Union, making up about 85 percent of global GDP and two-thirds of the world population.

But South Africa is currently the only G20 member from the African continent.

Amitabh Kant, India's G20 "sherpa", the official working behind the scenes to reach an agreement between members, said India had been "able to work with every single country and bring them on board", without giving details.

The Ethiopia-headquartered AU was created in 2002 following the disbanding of the Organisation of African Unity.

At full strength it has 55 members, but six junta-ruled nations are currently suspended. Collectively it has a GDP of $3 trillion with some 1.4 billion people.

India's top foreign service officer Vinay Kwatra said it expected a decision on AU membership would be made at the summit on Saturday morning.

However, the G20 is deeply divided on key issues from Russia's war in Ukraine to climate change, and it remains possible a member may veto the bid.

Azali Assoumani, president of the small Indian Ocean archipelago of Comoros and current head of the African Union, landed in New Delhi on Friday and was given a red-carpet welcome.

Assoumani, 64, is a former army chief-of-staff who took power in 1999 coup before retiring in 2006. He then returned to politics in 2016 to win a vote marred by violence and allegations of irregularities, and then won a disputed election in 2019.

In December, US President Joe Biden said he wanted the AU "to join the G20 as a permanent member", adding that it had "been a long time in coming, but it's going to come".

On Tuesday, Biden's national security advisor reiterated that stance when discussing US priorities for the New Delhi summit.

"We're also looking forward to warmly welcoming the African Union as a permanent member of the G20 -- the newest permanent member. We believe that the African Union's voice will make the G20 stronger," Jake Sullivan said at a White House briefing.