G20 summit: Five key takeaways

The G20 summit in New Delhi managed to defy expectations and reach consensus on a joint declaration by world leaders, but not without compromises over the Ukraine conflict and action on climate change.

Here are the five defining moments of the summit so far:

The Group of 20 leading economies began the weekend's proceedings by welcoming the African Union, the newest member of a bloc which already represented 85 per cent of world GDP.

Host and Indian prime minister Narendra Modi has portrayed this weekend as India's diplomatic coming of age, and his country's presidency as an opportunity to give a voice to the needs of the Global South.

Modi opened the summit's formal proceedings by inviting African Union president Azali Assoumani to take a seat alongside world leaders with the ceremonial bang of a gavel.

Before Saturday, the G20 comprised 19 countries and the European Union, with South Africa its only member state from the continent.

The African Union at full strength has 55 members but six junta-ruled nations are currently suspended. It has a collective GDP of $3 trillion with some 1.4 billion people.

G20 leaders have been deeply riven over the Ukraine war since Moscow's invasion last year, with Russian president Vladimir Putin skipping the summit entirely to dodge political opprobrium.

Facing the prospect of a major diplomatic embarrassment, host India pressed members to agree a common statement that watered down its earlier condemnation of the war.

In the end, the G20 denounced the use of force for territorial gain but refrained from direct criticism of Russia by name.

"There were different views and assessments of the situation," the leaders' statement said.

Kyiv's foreign ministry spokesman Oleg Nikolenko criticised the statement, saying the G20 had "nothing to be proud of".

Leaders failed to agree on a phase-out of fossil fuels, despite a UN report a day earlier deeming the drawdown "indispensable" to achieving net-zero emissions.

G20 nations account for around 80 percent of global emissions and an inability to agree on the phase-out is a cloud over a key round of climate discussions to begin in November in the oil-rich United Arab Emirates.

"We need stronger bolder action from leaders," said Madhura Joshi, senior associate at climate think tank E3G.

But for the first time the G20 backed a target of tripling global renewable energy capacity and referenced the need for emissions to peak before 2025.

It also acknowledged that limiting warming to 1.5 degrees Celsius will require slashing greenhouse gases 43 per cent by 2030 from 2019 levels.

A broad alliance including the United States and Saudi Arabia unveiled ambitious plans to create a modern-day Spice Route linking Europe, the Middle East and India.

If the initiative goes ahead, it would establish railways, ports, electricity and data networks and hydrogen pipelines in a counterbalance to lavish Chinese infrastructure spending.

One proposed project would link rail and port facilities across the Middle East, potentially speeding trade between India and Europe by up to 40 per cent.

The plans are also being touted as a means of helping normalise relations between Israel and Gulf Arab states.

"This is a real big deal," said US president Joe Biden, locking arms with Modi and Saudi Crown Prince Mohammed bin Salman in a triple handshake.

For days India has been abuzz with rumours that official usage of the country's English name would be dropped.

Modi gave the biggest signal yet of a potential change in his opening address to the summit, seated behind a country nameplate labelled "Bharat".

India and Bharat are both official names for the country under its constitution.

Modi himself typically refers to the nation as "Bharat", a word steeped in Hindu religious symbolism and dating back to ancient scripture.

Members of his Hindu nationalist party have campaigned against using the better-known moniker India, which has roots in Western antiquity and was imposed during the British conquest.