The United States and China, the world's two largest economies, will see if they can find a breakthrough to exit a spiraling trade war as their presidents meet at a tense G20 summit.
With markets watching nervously, U.S President Donald Trump has described the Buenos Aires summit of the 20 leading economic powers as a deadline for China to meet his demands or risk even further pressure.
The summit itself, with leaders from France, Russia and Saudi Arabia among those attending, has been struggling to carve out any accord on fighting climate change while hot-button disputes such as Ukraine loom large.
Trump, who has already slapped 250 billion in tariffs on China, sounded upbeat about making progress with his counterpart Xi Jinping after weeks of dire warnings.
"We're working very hard. If we could make a deal, that would be good," Trump told reporters Friday as he met Japanese Prime Minister Shinzo Abe on the first of the summit's two days.
"I think they want to, and I think we'd like to. And we'll see," Trump said.