The United States is not ruling out direct dialogue with North Korea on its nuclear program, Secretary of State Rex Tillerson said in an interview with National Public Radio broadcast Friday.

"Obviously, that would be the way we would like to solve this," he said, when asked whether Washington seeks direct talks with Pyongyang.

"But North Korea has to decide they're ready to talk to us about the right agenda -- and the right agenda is not simply stopping where they are for a few more months or a few more years and then resuming things."

Tillerson has previously said "the era of strategic patience is over." He stressed in the NPR interview that what Washington now seeks is dialogue.

"Our approach to North Korea is to have them change their posture towards any future talks," he said.

"I think when we say the era of strategic patience is over -- in the past I think we have always negotiated our way to the negotiating table... We don't have the running room left to do that now, given how far advanced their program has become.

"So this is an approach that is to put pressure on them through implementation of all the sanctions, as well as other diplomatic pressures, and calling on others to cause them to change their view of what will really allow them to achieve the security that they say they seek."

The United States has called for stronger UN sanctions on North Korea, but wants China to take the lead in diplomatic efforts to resolve the crisis.

Tillerson's interview came ahead of a UN Security Council meeting chaired by Tillerson, to push for a tougher response to North Korea and pile pressure on China to rein in its ally.

Chinese Foreign Minister Wang Yi will attend the meeting that follows weeks of warnings from the US administration that it will no longer tolerate North Korea's missile launches and nuclear tests.