Chinese leader Xi Jinping has urged Donald Trump to peacefully resolve tensions over North Korea’s nuclear programme, as the US president touted the power of a naval "armada" steaming towards the Korean peninsula.
China's foreign ministry said Wednesday the two leaders had spoken by phone, days after Trump sent the aircraft carrier-led strike group to the region in a show of force ahead of a possible nuclear test.
The deployment was followed by a renewed warning that Washington was ready to take on North Korea alone if Beijing declined to help rein in its maverick neighbour's nuclear ambitions.
Pyongyang has issued a defiant response, saying it was ready to fight "any mode of war" chosen by the United States and even threatening a nuclear strike against US targets.
The sabre-rattling has unnerved China, which has made clear its frustration with Pyongyang’s stubbornness but whose priority remains preventing any military flare-up that could bring chaos and instability to its doorstep.
In the call, Xi stressed that China "advocates resolving the issue through peaceful means," the foreign ministry said.
On Tuesday, the US president tweeted that "North Korea is looking for trouble. If China decides to help, that would be great. If not, we will solve the problem without them! U.S.A."
A barrage of recent North Korean missile tests has stoked US fears that Pyongyang may soon develop an intercontinental ballistic missile capable of delivering a nuclear warhead to the US mainland.
There is speculation that the country could be preparing a missile launch, or even another nuclear test, to mark the 105th birthday anniversary of its founder Kim Il-Sung on Saturday.
In an interview with Fox Business Network, Trump warned: "We are sending an armada. Very powerful."
"We have submarines. Very powerful. Far more powerful than the aircraft carrier."
The flotilla includes the Nimitz-class aircraft supercarrier USS Carl Vinson, a carrier air wing, two guided-missile destroyers and a guided-missile cruiser.
"This goes to prove that the US reckless moves for invading the DPRK have reached a serious phase," a spokesman for the North's foreign ministry said in response.
Chinese foreign ministry spokesman Lu Kang said Wednesday it was "irresponsible and even dangerous to take any actions that may escalate the tension".
"All relevant parties should exercise restraint and keep calm, easing tensions instead of provoking each other and adding fuel to the fire," he said at a regular press briefing.
Pyongyang has so far staged five nuclear tests, two of them last year, and analysis of satellite imagery suggests it could be preparing for a sixth.
China's Global Times newspaper, which sometimes reflects the thinking of the country's leadership, said a new test would be a "slap in the face of the US government" and that Beijing would not "remain indifferent".
"Presumably Beijing will react strongly to Pyongyang's new nuclear actions," it said, adding there was increasing popular support for "severe restrictive measures that have never been seen before".
The language suggested China -- the North's sole major ally and economic lifeline -- could restrict oil imports to the country, after already announcing a suspension of all coal imports until the end of the year.
- 'Outstanding' relationship -
The call between the leaders of the world's largest economies followed their first face-to-face meeting late last week.
During the call, Xi told Trump that China remains "willing to maintain communication and coordination with the American side on the issue of the peninsula," according to the foreign ministry.
Trump, it added, said it was vital for the two heads of state to maintain close ties.
The high-profile summit in Florida was overshadowed by a US missile strike on Syria that was also interpreted as a warning to North Korea.
Xi told Trump on the call that the Syria issue "must continue to move towards a political solution", and that "any use of chemical weapons is unacceptable".
He said their summit produced "significant results", and that both sides would work together to ensure Trump visited China later this year.
Trump's election campaign was marked with acerbic denouncements of the Asian giant's "rape" of the US economy and his vow to punish Beijing with punitive tariffs.
But he dropped his anti-China bombast in Florida, afterwards hailing an "outstanding" relationship with his Chinese counterpart.