G20

German Chancellor Angela Merkel said the country should not be allowed to "descend into chaos".

The virtual summit came as the UN urged world leaders to put billions of dollars into the Afghan economy.

US President Joe Biden stressed that aid should be provided via independent international organisations and not directly to the ruling Taliban.

But so far the money forthcoming has largely been counted in millions, just to provide emergency food and medicine.

The two leaders were conversing on the sidelines of the Group of 20 summit here, according to a US National Security Council spokesman. More details about their discussion were expected later Monday, but US officials said before the summit that Syria and Ukraine would likely be on the agenda of an Obama-Putin huddle.

The same could be said about the post-referendum debate. The phrase "Brexit means Brexit" has seen the government through the summer, but has now reached the end of its usefulness.

It was designed to persuade doubting Remainers that the UK really will leave the EU, something Theresa May was once again forced to confirm during her news conference with President Obama here in China.

But over the months the slogan has inverted into something different, a symbol of the government's uncertainty about what Brexit will actually mean for our relationship with the EU.