The first G20 summit to be held in Africa has opened – without US president Donald Trump.

Leaders and senior government officials from around the world have gathered in South Africa for the two-day summit, which aims to make progress on solving some of the problems which are afflicting the world’s poorest nations.

Prime Minister Sir Keir Starmer is in Johannesburg for the summit – and he spoke about the bloc’s “critical” importance on its first day.

“The role of the G20 is critical at this moment,” said Sir Keir, who has defended his decision to fly to the G20 days before a difficult budget.

“Growth must be a mission for us all to embrace as the means to improve lives, fund public services and to keep our people secure.

“The G20 has worked together before to fix fundamental problems in the global Economy. We need to find ways to play a constructive role again today in the face of the world challenges.

“I’d like to see us come together around a five-point plan for growth that leaves no one behind.”

The US, however, is boycotting the talks. The Trump administration made its opposition to South Africa’s G20 agenda clear earlier this year when the country started holding meetings ahead of the summit.

Marco Rubio, the US secretary of state, skipped a foreign ministers meeting in February, and said that he would not waste American taxpayers money on an agenda which was focused on diversity, equity and inclusion and climate change.

South Africa gets to set the agenda as the country holding the rotating G20 presidency.

G20 leaders broke with tradition and adopted a declaration at the start of their summit – despite opposition from the US.

Vincent Magwenya, spokesman for South African president Cyril Ramaphosa, said a leaders’ declaration was adopted unanimously in Johannesburg.

Mr Magwenya said: “Normally the adoption of the declaration happens right at the end. But … there was a sense that we should actually move to have the summit declaration adopted first as the first order of the day.”

There were no details of what was in the declaration, but South Africa has promoted it as a victory for the summit.

The G20 bloc was formed in 1999 as a bridge between rich and poor nations to confront global financial crises.

While it often operates in the shadow of the powerful Group of Seven nations, G20 members represent around 85% of the world’s economy, 75% of international trade and more than half the global population.