Chinese leader Xi Jinping hailed the US-China relationship during President Donald Trump’s visit, but warned that Taiwan could prove a flashpoint and that the superpowers needed to avoid a “Thucydides trap” that could trigger conflict.

The relatively upbeat start to the eagerly awaited summit did not yield immediate breakthroughs on key points. Xi is keen to limit US arms sales to Taiwan and wants Washington to outright oppose Taiwanese independence, major concessions that Trump is unlikely to make, while the US leader is pushing Beijing to open its economy to American firms.

China also wants looser US controls on advanced semiconductors, again a difficult proposition, while Trump is eager to extend a pause on Chinese rare-earths export restrictions.