BEIJING, China (AFP) — Washington has opened channels to North Korea to find out if the regime is ready to talk about giving up its nuclear weapons, Secretary of State Rex Tillerson said Saturday. His office in Washington quickly clarified that North Korea has shown no interest in such discussions.

Speaking after a day of talks with China’s President Xi Jinping and top diplomats, Tillerson told reporters that US officials are in touch with Pyongyang.

The disclosure follows an escalating war of words between US President Donald Trump and North Korean strongman Kim Jong-Un, and Tillerson issued a call for calm.

Asked how he could know whether the North would even contemplate responding to new sanctions by coming to the table, the US envoy said: “We are probing, so stay tuned.”

Washington has no diplomatic ties with Kim’s autocratic regime, and has been leaning on Beijing to rein in its neighbour’s behaviour through tougher sanctions.

But Tillerson said US diplomats do not rely on China as a go-between in overtures to North Korea, and have themselves talked directly through “our own channels”.

“We ask,” he said. “We have lines of communication with Pyongyang. We’re not in a dark situation, a blackout, we have a couple, three channels open to Pyongyang.”

“We can talk to them, we do talk to them,” he said.

In Washington, the State Department said that while such communications channels do exist North Korea has shown no interest in talking about giving up its nuclear weapons.

“Despite assurances that the United States is not interested in promoting the collapse of the current regime, pursuing regime change, accelerating reunification of the peninsula or mobilising forces north of the DMZ, North Korean officials have shown no indication that they are interested in or are ready for talks regarding denuclearisation,” department spokeswoman Heather Nauert said in a statement.

The US has not ruled out the use of force to compel Pyongyang to halt missile and nuclear tests, and last week Trump threatened to “totally destroy” the country.

But privately senior figures admit the military options do not look promising, with ally South Korea’s densely populated capital Seoul in range of the North’s artillery.