US and Japanese foreign and defence ministers warned Tuesday against "coercion and destabilising behaviour" by China after top-level talks in Tokyo.

Pentagon chief Lloyd Austin and Secretary of State Antony Blinken are in Japan on the first leg of their first overseas trip, looking to strengthen regional alliances in the face of rising Chinese influence.

In a joint statement issued after bilateral and joint talks with their Japanese counterparts, they warned that "China's behaviour, where inconsistent with the existing international order, presents political, economic, military and technological challenges."

"The ministers committed to opposing coercion and destabilising behaviour towards others in the region," they added.

Both sides also expressed "serious concerns about recent disruptive developments in the region", directly referencing recent Chinese moves.

The talks come with US President Joe Biden's administration looking to reset regional alliances after the tumult of the Donald Trump era.

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Austin and Blinken are also consulting regional allies as part of a review of Washington's policy towards North Korea, which lashed out at the administration earlier Tuesday.

The ministers' joint statement called again for Pyongyang's "complete denuclearisation" warning North Korea's arsenal "poses a threat to international peace and stability".

But Blinken refused to offer any comment on remarks from Kim Jong Un's sister, who warned Washington against "struggling to spread the smell of gunpowder on our land from across the ocean".

"We're looking at whether various additional pressure measures could be effective, whether there are diplomatic paths that make sense, all of that is under review," Blinken said.

"Going forward we have a shared determination to deal with the challenge posed by North Korea, particularly when it comes to its nuclear missile programmes, as well of course as its abuse of human rights," he added.