Chinese President Xi Jinping opened the annual G20 summit by emphasising the need for the world's 20 largest economies to safeguard growth by co-ordinating their economic policies.

Much of the first day of the summit in the eastern city of Hangzhou has been taken up in a series of bilateral meetings.

Discussions included regional security, trade and climate change. World leaders have gathered in the Chinese city of Hangzhou for the annual G20 summit of the biggest economies. 

It is the first time that China has hosted the meeting.

The main item on the agenda is the health of the global economy. 

At a news conference on the sidelines of the summit President of the European Council, Donald Tusk, said Europe was "close to limits" on its ability to accept new waves of refugees, and urged the broader international community to “scale up” its share of responsibility.

The UN Secretary General Ban Ki Moon said the sluggish recovery from the financial crisis still threatens many smaller countries.

Yesterday, he praised the US and China on the eve of the summit for ratifying the Paris agreement on cutting greenhouse gas emissions

Meanwhile, British Prime Minister Theresa May warned of possible "difficult times ahead" for Britain's economy in an interview screened today as she sought to build post-Brexit trade ties at the summit.

Speaking to BBC television, Ms May also ruled out a new general election in the near future, saying Britain needed stability following June's referendum vote to pull out of the European Union.

"I'm not going to pretend that it's all going to be plain sailing," she said. "I think we must be prepared for the fact that there may be some difficult times ahead. But what I am is optimistic."

"I'm not going to be calling a snap election," Ms May said.

"I've been very clear that I think we need that period of time, that stability, to be able to deal with the issues that the country is facing and have that election in 2020."