The United States is communicating with North Korea as it seeks to encourage the regime to abandon its build up of nuclear weapons, Secretary of State Rex Tillerson said.
Mr Tillerson made his comments in Beijing after holding talks with Chinese leaders on Saturday amid rising concerns over Pyongyang’s military programme.
Washington is known to have back channels which it uses to help negotiate the release of US citizens who have been held captive in the North.
But Mr Tillerson’s disclosure suggests US officials are also using secret talks to convince Pyongyang to hold official negotiations aimed at easing tensions.
“We are probing, so stay tuned,” he told reporters.
“We ask. 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.
Asked whether China was acting as a go-between for the contacts, Mr Tillerson said: “Our own channels.”
Tensions have increased in northeast Asia with Kim Jong-un’s regime carrying out a series a missile tests and detonating a nuclear bomb earlier this month.
South Korean media reported on Saturday that North Korean missiles were being moved from a research facility, suggesting another provocation could be imminent.
During his visit to Beijing, Mr Tillerson also discussed arrangements for a trip by Donald Trump to China in November, and Mr Xi spoke about his close relationship with the US President.
He has met him in Florida in April and at the G20 summit in Hamburg in July. The leaders have also held several phone calls.
“I have enjoyed each and every one of those engagements and we have made considerable efforts to push for the development of China-US relations,” Mr Xi said.