TOKYO - SOUTH Korean President Lee Myung-Bak was due to meet Japanese Prime Minister Taro Aso for talks Sunday with simmering tensions over North Korea's nuclear programmes topping the agenda.

The summit comes as Pyongyang steps up its confrontational rhetoric amid global suspicions that the regime is preparing to fire more missiles and stage a military exercise in waters off its east coast.

Regional tensions spiked after North Korea last month carried out an underground nuclear test for the second time, followed by missile launches.

The two leaders are likely to discuss implementation of UN sanctions which call for tougher inspections of cargo suspected of containing banned missile and nuclear-related items.

Mr Lee and Mr Aso are expected to reiterate their calls on China to help pressure North Korea to heed the wishes of the international community and to drop its nuclear ambitions.

North Korea has vowed to build more bombs and to start a new weapons programme based on uranium enrichment in response to the UN sanctions.

Tokyo and Seoul have led the push in East Asia against the North's increasingly antagonistic stance as Pyongyang repeated warnings of military confrontation.

North Korea warned Thursday that 'dark clouds of nuclear war' are gathering over the peninsula and vowed to strengthen its atomic arsenal as it marked the anniversary of the 1950-1953 Korean war.

Mr Lee's one-day trip to Tokyo is part of 'shuttle summit diplomacy,' a system that sees the leaders visit each other twice a year for talks on issues including diplomatic and economic matters.

They are also expected to hear from a group of Japanese and South Korean business leaders on ways to tighten bilateral economic relations.

Other topics on the agenda are likely to be efforts towards the resumption of free trade talks, global recession and helping Afghanistan and Pakistan in their battle against militants. -- AFP