Secretary of State Rex Tillerson has said that the US is in “direct contact” with North Korea.
He also said Washington was “probing” the possibility of talks with Pyongyang, “so stay tuned”.
During a trip to China, Rex Tillerson said: “We have lines of communications to Pyongyang.
“We’re not in a dark situation.”
In recent months, North Korea and the US have engaged in heated rhetoric, but it was not previously known they had lines of communication.
President Donald Trump has threatened to annihilate North Korea, saying Kim Jong-un, “is on a suicide mission”, which led the North Korean leader to release a statement vowing to “tame the mentally deranged US dotard with fire”.
On September 30, North Korea continued the rhetoric, releasing a statement calling President Trump an “old psychopath” bent on the “suicidal act of inviting a nuclear disaster that will reduce America to a sea of flames”.
The war of words comes against a backdrop of repeated missile tests and North Korea’s claim that, on September 3, it successfully tested a miniaturized hydrogen bomb which could be loaded on to a long-range missile.
The tests were internationally condemned, with the UN bringing in sanctions against the secretive country in an attempt to force it to stop its weapons program.
Rex Tillerson is in China meeting with President Xi Jinping and other officials, hoping to encourage them to implement the sanctions.
China this week told North Korean businesses operating in its territory to close down. However, China remains keen to see negotiations with North Korea.
President Trump said last month that “talking is not the answer”.
However, there were reports of so-called back channels between the two administrations.
According to the Associated Press, the US and North Korea had been engaged in quiet discussions for months, with “diplomatic contact… occurring regularly” between the US envoy for North Korea policy and “a senior North Korean diplomat at the country’s UN mission”.
Rex Tillerson has also previously hinted there are channels available between the two countries, AP added.
More widely known is the role Sweden plays in negotiating with North Korea on Washington’s behalf.
In August, Ulv Hanssen from the Swedish Institute of International Affairs told Reuters Sweden could step in again because it was trusted by both US and North Korea.
“Sweden has done so on numerous occasions before, especially in relation to imprisoned Americans,” he said.
The Swedish Foreign Ministry declined to comment on the speculation.