Chinese President Xi Jinping and US Secretary of State Rex Tillerson pledged in talks on Sunday to work to strengthen a relationship strained by disputes over North Korea and trade.
Xi met Tillerson in Beijing just hours after nuclear-armed North Korea tested the US-China relationship anew by announcing a provocative rocket engine trial, and with delicate negotiations under way for a Xi summit with President Donald Trump.
Xi told Tillerson that he and Trump had resolved in a phone call last month "to make joint efforts to advance China-US cooperation, and we believe that we can make sure the relationship will move ahead in a constructive fashion in the new era."
"I'm confident that as long as we can do this the relationship can surely move in the right direction," Xi said.
En route to Beijing, Tillerson visited US allies Japan and South Korea where he declared Washington would drop the "failed" approach of "strategic patience" with Pyongyang -- adding that US military action against the North was possible.
That marked a sharp break with China, which favours careful diplomacy over heated rhetoric.
Relations have also been strained by China's fierce opposition to a US missile defence system being rolled out in South Korea and Trump's Twitter accusation on Friday that China was not doing enough to control Pyongyang, its neighbour and historic ally.
Trump has also repeatedly accused China of unfair trade practices.
But Tillerson has made nice while in Beijing.
"We know that through further dialogue we will achieve a greater understanding that will lead to a ... strengthening of the ties between China and the United States and set the tone for our future relationship of cooperation," he told Xi.
Earlier Sunday North Korean state media said the isolated regime had tested a powerful engine hailed by leader Kim Jong-Un as a "new birth" for its rocket industry, which experts view as cover for developing intercontinental ballistic missiles.
- Rocket 'rebirth' -
The announcement's timing appeared intended to sour Tillerson's China visit.
On Saturday Tillerson said after talks with his Chinese counterpart Wang Yi that tensions on the Korean peninsula had reached a "dangerous level".
Tillerson and Wang pledged to work together to denuclearise Kim's rogue regime, but offered no clear way forward.
Wang, however, chided Tillerson over his recent tough talk, saying "we hope all parties, including our friends from the United States, can size up the situation in a cool-headed" fashion.
It was not clear whether Xi and Tillerson discussed North Korea.
The North's state news agency KCNA said Kim oversaw the rocket engine test and "emphasised that the whole world will soon witness what eventful significance the great victory won today carries" -- a possible veiled warning to Pyongyang's adversaries.
Ruling party newspaper Rodong Sinmun splashed photos across its front page showing a beaming, baton-wielding Kim looking on as flames roared out of the engine.
State TV also showed Kim meeting soldiers and scientists at the site and hugging and giving a piggy-back to an aged soldier who appeared to be bursting into tears in joy.
KCNA said the new engine could be used to launch satellites, but rockets are easily repurposed to carry warheads.
North Korea is banned by the international community from pursuing nuclear and missile programmes but has defiantly ploughed ahead.
It staged its two latest nuclear tests last year and recently fired off missiles which it described as practice for an attack on US bases in Japan.
Kim said the successful engine test signified "a new birth" of North Korea's rocket industry.
- Summit in the works -
Xi met Tillerson as the two sides haggle behind closed doors over a summit with Trump, a frequent China critic.
A successful meeting could be crucial in setting the tone for the relationship between the world's two largest economies in coming years.
Officials who spoke on condition of anonymity have told AFP that Trump has tentatively agreed to host Xi at his Mar-a-Lago resort in Florida in early April.
But they said the plan was running up against differences over North Korea, what "deliverables" can emerge, and anger over leaks about the planning.
It remained unclear whether Tillerson's apparently cordial Beijing visit would now pave the way.
Tillerson mentioned "the opportunity for a visit in the future" but otherwise gave no further details. He left China without speaking to media.
Coverage of the low-profile trip has been complicated by the decision to travel without the usual press pack -- a break with a half-century of tradition.
Instead, Tillerson angered US and foreign correspondents accredited to cover the State Department by travelling with just one journalist -- from a little-known conservative publication called the Independent Journal Review.