The United States and China held last-minute talks in South Korea on Wednesday to set the agenda for Donald Trump's summit with Xi Jinping in Beijing later this week.
Officials from both sides met at the Incheon airport after separate meetings with South Korean president Lee Jae Myung.
US treasury secretary Scott Bessent and Chinese vice premier He Lifeng led the discussions, which are expected to cover a broad agenda for the Beijing summit running Thursday to Friday.
China's lead trade negotiator, vice commerce Minister Li Chenggang, and vice finance Minister Liao Min were among the officials accompanying Mr He. Analysts said the airport talks were likely exploratory rather than decisive.
"Both sides are essentially in a holding pattern ahead of the summit, sounding each other out, rather than seeking breakthroughs," Kim Tae-hwang, professor of international trade at Myongji University in Seoul, told Reuters.
The leaders of the world's two largest economies will hold their first face-to-face talks in more than six months this week as they try to stabilise ties.
At the Beijing summit, the leaders are expected to agree to set up forums to ease mutual trade and investment, while China is expected to announce purchases related to Boeing aircraft, American agriculture and energy, US officials said. Beijing also wants Washington to relax curbs on exports of advanced semiconductors and has raised concerns about legislation that would restrict shipments of critical chip-making equipment to China.
The two sides are also considering extending a truce on China's export restrictions on rare earths, the materials vital for defence and manufacturing, though Chinese customs data shows Beijing is still throttling shipments of the materials.
The Iran war is also expected to feature in the discussions. China maintains ties with Tehran and is the world's largest buyer of Iranian oil, making Beijing a potentially important player in any diplomatic resolution.
Mr Trump said on Tuesday he did not think he would need China's help to end the conflict, even as hopes for a lasting peace deal dwindled and Tehran tightened its grip on the Strait of Hormuz.
"I don't think we need any help with Iran. We'll win it one way or the other, peacefully or otherwise," he told reporters when departing the White House for China.
Neither side has strong incentives to make early concessions, Mr Kim said. The US is unlikely to ease curbs on key technologies such as semiconductors, while China, buoyed by relatively resilient growth and trade performance, is under less pressure to offer significant compromises.
The Republican president is scheduled to arrive in Beijing on Wednesday, ahead of talks set to take place Thursday and Friday. It will be his first trip to China since 2017.
Mr Trump later told reporters: "We have a lot of things to discuss. I wouldn't say Iran is one of them, to be honest with you, because we have Iran very much under control."
