US secretary of state Mike Pompeo has met Japanese PM Shinzo Abe to make sure the two allies are on the same page before Pompeo travels to North Korea, where he will be under pressure to push Pyongyang towards giving up its nuclear weapons.

His diplomatic offensive in Asia comes as President Donald Trump seeks to meet North Korean leader Kim Jong Un for a second time after their June summit in Singapore.

Pompeo told Abe it was important for him to hear from the Japanese leader "so we have a fully co-ordinated and unified view" to successfully denuclearise North Korea.

He is also meeting his Japanese counterpart Taro Kono before heading to Pyongyang on Sunday. Tokyo is the first stop of his three-day east Asia tour, which also takes him to South Korea and China.

In Beijing, Pompeo will face tensions over trade and accusations of election interference.

Japanese chief cabinet secretary Yoshihide Suga told reporters Pompeo and the Japanese planned to work on deepening their co-operation in their efforts to achieve North Korea's denuclearisation.

The real diplomatic test for Pompeo will come in Pyongyang. He is expected to meet Kim Jong Un and one of his most trusted aides, Kim Young Chol, a former intelligence official.