Beijing, Apr 28 (IANS): US Secretary of State Rex Tillerson said that China threatened North Korea with sanctions if it undertook another nuclear weapons test, the media reported.

Tillerson made his comments on Thursday ahead of a visit to the UN and amid rising tensions over the North Korean nuclear weapons programme, CNN reported.

"They confirmed to us that they had requested that the regime conduct no further nuclear test," Tillerson said of the Chinese.

"In fact, we were told by the Chinese that they informed the (North Korean) regime that if they did conduct further nuclear tests, China would be taking sanctions action on their own."

Tillerson said he was hopeful about cooperation with the Chinese. He also said he believed North Korean leader Kim Jong-un is rational.

"He may be ruthless...He may be a murderer. He may be someone who, in many respects, we would say by our standards is irrational. But he is not insane."

North Korea conducted its fifth nuclear test late last year, and observers have said a sixth test may come soon, reports CNN.

The Secretary of State said the US approach to North Korea under Trump is different from former President Barack Obama's in terms of both "intensity" and "expectations".

"We're asking a lot of the Chinese," Tillerson said. "I think in the past, the assumption has been the Chinese would only take limited action. We're going to test that assumption."

North Korean official Sok Chol Won told CNN on Wednesday that the country's government would never stop nuclear and missile tests "as long as America continues its hostile acts of aggression".