WASHINGTON (AFP) - China should press North Korea to give up its nuclear weapons if Beijing wants to change US troop plans in the region, a US official said Tuesday.

Danny Russel, the assistant secretary of state for East Asia, acknowledged that a growing China has been unhappy with efforts by the United States to strengthen defence cooperation with allies Japan and South Korea.

"The most direct way for China to affect those military deployments and those strategic alliance plans is by applying its leverage to North Korea to bring about a decision on the part of Pyongyang to choose the right path," Mr Russel told a conference call organised by the Asia Society.

China is the closest ally of North Korea and has voiced growing frustration over the regime's nuclear program, although US experts widely believe that Beijing does not want to risk the collapse of Kim Jong-Un's regime.

Russel credited China with supporting UN Security Council resolutions that toughened sanctions and with restricting its own exports into North Korea.

But he said that Chinese officials "have a strong bias in favor of coaxing tactics that have not yielded results in the past and that don't seem likely to yield results." "China should and hopefully will take further steps to bring North Korea to the conclusion that it has no viable alternative but to come into compliance" with international agreements on ending its nuclear program, Mr Russel said.

North Korea has defied the world with three nuclear weapons tests and, according to a recent UN investigation, carries out sweeping human rights violations without parallel in the current world.

Tensions have again risen in recent days, with North and South Korea firing hundreds of artillery shells Monday as Seoul responded to a live-fire drill by Pyongyang.