The African Union is to become a member of the G20, after been invited to join on 9 September 2023, at the group's summit in India's capital Delhi.
The African Union will represent 55 countries from across the continent at future G20 meetings.
What is the G20?
The G20 - or Group of Twenty - is a club of countries that meets to discuss global economic and political issues.
Between them, G20 countries account for 85% of the world's economic output and more than 75% of world trade. They contain two-thirds of global population.
The G20 members are the EU plus 19 nations: Argentina, Australia, Brazil, Canada, China, France, Germany, India, Indonesia, Italy, Japan, Mexico, Russia, Saudi Arabia, South Africa, South Korea, Turkey, the UK and the US.
Some countries which are members of the G20 also meet as the G7. These are the world's seven leading industrialised countries.
The African Union was invited to be become a permanent G20 member at the Delhi summit. The organisation represents 55 African countries.
Why was the G20 set up, and why does it matter?
The group was founded in 1999 after the Asian financial crisis. It was designed to be a forum for finance ministers and officials to discuss ways to restore economic stability.
The first leaders' summit was held in 2008 in response to that year's global financial turmoil, to promote international cooperation.
The G20 has broadened its focus in recent years to include issues such as climate change and sustainable energy.
Every year, a different G20 member state takes over the presidency, and sets the agenda for the leaders' summit.
What did the G20 summit achieve?
A joint declaration from G20 members condemned"human suffering and adverse repercussions of the conflict in Ukraine on global food and energy security", without directly criticising Russia.
The Ukrainian government said the declaration was "nothing to be proud of", adding that a Ukrainian presence would have given participants a better understanding of the situation.
A new network of railways and shipping routes was announced by the US, India, Saudi Arabia and the EU, on the sidelines of the summit. It is designed to increase trade between South Asia, the Middle East and Europe.
It is also meant to counter China's project to build new global trading routes, the Belt and Road Initiative.
India's Prime Minister Narendra Modi had wanted the summit to promote his country as a major global power, and himself as an important world leader, ahead of a general election due in spring 2024.
He took the lead in inviting the AU to become a permanent member to the G20.
Both Russia's President Vladimir Putin and China's President Xi Jinping stayed away from the summit.
Which issues proved difficult for the G20?
In May 2023, China and Saudi Arabia boycotted a G20 meeting on tourism, which was held in Indian-administered Kashmir, because the Kashmir region contains territory claimed by Pakistan as well as India.
A row also broke out between India and China shortly before the summit, when Beijing released a map claiming the state of Arunachal Pradesh and the Aksai Chin plateau as Chinese territory.
What have former G20 summits achieved?
At the 2008 and 2009 leaders' summits, during the financial crisis, leaders agreed a host of measures to rescue the global economic system.
But some critics argue that subsequent summits have been less constructive, often because of tensions between rival world powers.
However, one-to-one meetings between leaders have often proved constructive.
For example, at the 2019 summit in Osaka, then-US president Donald Trump and Chinese President Xi Jinping agreed to resume talks to settle a major trade dispute.
What are the security issues at G20 summits?
G20 summits attract anti-globalisation protests.
India's government ramped up security measures ahead of the Delhi event, closing roads around the venue, and deploying130,000 security officials across the city.
Novel measures were also taken to try to keep troublesome monkeys away from the area.
Delhi has a huge monkey population and authorities needed to stop the animals from disrupting the summit.