North Korea warns U.S. and South of nuclear build-up

SEOUL (Reuters) - North Korea said on Sunday it will bolster its atomic arsenal and was no longer bound by the cease fire that ended the Korean War due to joint U.S.-South Korean military drills, which start this week.

The comments come just days after a senior diplomat from China, the destitute North's biggest benefactor, said Beijing wants stalled international talks aimed at ending North Korea's nuclear arms activities to restart before July.

The warning from the North, typical of the heated rhetoric it issues to coincide with the drills, will not likely cause any increased risk to the troubled peninsula, analysts said.

North Korea routinely denounces the annual U.S.-South Korean military drills as a prelude to invasion and nuclear war even though they have been held for decades without major incident.

"The process for the denuclearization of the Korean peninsula will naturally come to a standstill," the North's official KCNA news agency quoted a senior military official as saying.

"It is illogical to sit face to face with the dialogue partner, who brings dark clouds of a nuclear war while leveling its gun at the other party, and discuss 'peace' and 'cooperation' with him," the official was quoted as saying.

The Key Resolve/Foal Eagle drills run from Monday to March 18 and involve thousands of troops.

The North has come under pressure to return to six-country disarmament-for-aid nuclear talks due to U.N. sanctions imposed after a May 2009 nuclear test. The sanctions have dealt a blow to its wobbly economy, and a botched currency move late last year has sparked inflation and rare civil unrest.

The two Koreas are technically still at war because their 1950-53 conflict ended with an armistice and not a peace treaty.

The United States, which fought on behalf of the South during the war, has about 28,000 troops in the country to support its 670,000 soldiers. The North's deploys most of its 1.2 million troops near the border with the South.

(Reporting by Jon Herskovitz)