Kerry hails Chinese North Korea pledge
US Secretary of State John Kerry says China is "very serious" about a pledge to help resolve tensions over North Korea's nuclear programme.
The US and China earlier said they were committed to the "denuclearisation" of the Korean peninsula and would hold further meetings on how to do so.
Mr Kerry is now continuing his Asian tour in Tokyo.
North Korea has recently threatened attacks against South Korea and the US, amid a flurry of bellicose statements.
Speculation has also built that the North was preparing a missile launch, following reports that it had moved at least two Musudan ballistic missiles to its east coast.
Mr Kerry has said any such launch would be a "huge mistake".
After a day of meetings in Beijing with President Xi Jinping and other top Chinese officials on Saturday, he said both governments called on North Korea "to refrain from any provocative steps and that obviously refers to any future missile shoot".'Not just rhetoric'
Following Mr Kerry's meetings, China's top diplomat Yang Jiechi said his country's position was "clear cut".
After weeks of rising tensions, and North Korea's threats of nuclear war, the diplomatic efforts to tackle this crisis are gathering pace.
The pledge to work with the US is a clear signal of China's displeasure with North Korea. China is North Korea's only ally, and is not going to stop supporting the North, but wants it to calm things down.
The question is will North Korea listen? In recent weeks the North's regime has made clear it now views having nuclear weapons as vital to its survival.
It has said explicitly that it won't bargain them away.
"China is firmly committed to upholding peace and stability and advancing the denuclearisation process on the Korean peninsula," he said, adding that the issue should be resolved "peacefully through dialogue".
No specifics were given, though Mr Kerry said the two sides would hold "further discussions to bear down very quickly with great specificity on exactly how we will accomplish this goal".
He later told reporters that the US Chairman of the Joint Chiefs of Staff, Martin Dempsey, would visit Beijing later this month accompanied by intelligence officials.
He said he wanted to ensure that the pledges made on Saturday were "not just rhetoric", adding: "There is no question in my mind that China is very serious - very serious - about denuclearising."
China is North Korea's only ally and major trading partner, but has grown increasingly frustrated with its growing belligerence.
Even so, the BBC's Damian Grammaticas reports from Beijing that persuading China to increase the pressure on North Korea will not be easy.
China is still the North's lifeline, and Beijing is unlikely to cut vital supplies of food and fuel since it feels that may make the North even more desperate and unpredictable, our correspondent adds.
On Sunday, Mr Kerry is meeting his Japanese counterpart Fumio Kishida and Prime Minister Shinzo Abe in Tokyo, where he is expected to reassure Japan of America's continued support during the crisis.'Forward-leaning posture'
On Saturday Mr Kerry raised the prospect that if North Korea stopped its nuclear programme - "if the threat disappears" - then the US would no longer have "the same imperative... to have that kind of robust, forward-leaning posture".
Since the UN imposed fresh sanctions on North Korea in February in response the North's third nuclear test, Pyongyang has promised to restart a mothballed nuclear reactor and threatened a nuclear strike against the US mainland.
- The Musudan, also known as the Nodong-B or the Taepodong-X, is an intermediate-range ballistic missile. Its likely targets are Okinawa, Japan, and US bases in the Pacific
- Range estimates differ dramatically. Israeli intelligence suggests 2,500km, while the US Missile Defense Agency estimates 3,200km; other sources put the upper limit at 4,000km
- These differences are due in large part to the fact that the missile has never been tested publicly, according to the Center for Nonproliferation Studies. Its payload is also unknown
It has also shut an emergency military hotline to South Korea, and urged diplomatic staff to leave, saying it cannot guarantee their safety.
The North says it has also been angered by joint US-South Korean military exercises.
On Saturday, a commentary piece on Chinese state news agency Xinhua said Washington had itself "been fanning the flames" by sending military reinforcements to the region.
But during his trip, Mr Kerry has stressed that the US has tried to tone down its own statements, and cancelled some military exercises in an effort to defuse tension.
Though North Korea's rhetoric has been more bellicose than usual, analysts say it fits a long-standing pattern, and may be intended to boost the popularity of Kim Jong-un, who came to power last year.
Some estimates suggest that the missiles North Korea has moved to its east coast could travel 4,000km (2,500 miles), although it is not believed that the Musudan has been tested before.
That would put US bases on the Pacific island of Guam within range.
But US officials including Mr Kerry have been playing down a leaked Pentagon report which warned that Pyongyang could have developed the technology to mount a nuclear warhead on a missile.