China and the US - Iran's key partner and its chief adversary - found firmer common ground on Tehran at the Washington summit last month, and further head-of-state diplomacy could work in Iran's favour, according to analysts. Iran was on the agenda when the presidents of the United States and China met in Beijing in May and again in Washington in September. There was no direct reference to Tehran in Beijing's statement after the May summit, but following the September meeting China was more specific, saying it and the US agreed that Iran must uphold its commitment against developing nuclear weapons. Do you have questions about the biggest topics and trends from around the world? Get the answers with SCMP Knowledge, our new platform of curated content with explainers, FAQs, analyses and infographics brought to you by our award-winning team. In an eight-point consensus, the two powers also agreed that no country or organisation should impose tolls on international waterways, according to the Chinese foreign ministry. Chinese state news agency Xinhua also reported that Xi Jinping said in Was