Kerry in China amid North Korea tensions

US Secretary of State has arrived in Beijing where he is expected to meet with top Chinese officials and urge them to use their considerable influence over North Korea to calm rising tensions in the region.

Ahead of Saturday's visit, Kerry called on China to take a more active stance toward North Korea, which in recent weeks has threatened nuclear war against the US.

As North Korea's main trading partner, financial backer and diplomatic ally, Kerry said China has a unique ability to use its leverage against the impoverished, isolated state, Kerry said in the South Korean capital Seoul late on Friday.

"There is no group of leaders on the face of the planet who have more capacity to make a difference in this than the Chinese, and everybody knows it, including, I believe, them," Kerry told US executives.

"They want to see us try to reach an amicable resolution to this," he said.

"But you have to begin with a reality, and the reality is that if your policy is denuclearisation - and it is theirs as it is ours as it is everybody's except the North's at this moment - if that's your policy, you've got to put some teeth into it," he said.

In his first official visit to China as US secretary of state, Kerry is scheduled to meet the top echelon of the Chinese leadership on Saturday.

He will lunch with Foreign Minister Wang Yi, then see President Xi Jinping, Premier Li Keqiang and finally State Councillor Yang Jiechi, China's top diplomat who outranks Wang.

His visit to Asia, which will include a stop in Tokyo on Sunday, takes place against after weeks of North Korean threats of an impending war since the imposition of new UN sanctions in response to its third nuclear test in February.