S Korea-US military exercise begins in the Sea of Japan

S Korea-US military exercise begins in the Sea of Japan

The US and South Korea have begun a major military exercise in the Sea of Japan, despite threats of retaliation from North Korea.

The navy and air force manoeuvres involve 20 ships, 200 planes and 8,000 US and South Korean personnel.

Washington and Seoul say they want to send a clear signal to the North following the sinking of a South Korean warship in March.

An international investigation said a North Korean torpedo sank the ship.

However, the claim has been angrily denied by Pyongyang.

On Saturday, North Korea threatened to use its nuclear deterrent in a retaliatory, "sacred war" in response to the exercise.

The BBC's John Sudworth, who is aboard one of the warships, says the show of strength is intended to rattle Pyongyang's military and political elite.

But some observers are questioning whether the display of military power will simply galvanise the hardliners inside the isolated country, he says.

North Korea's inflammatory rhetoric is nothing new, he adds, but the rising tension is causing concern, with China urging all parties to show restraint.

The South Korean defence ministry said the manoeuvres had been relocated from the sensitive Yellow Sea to the Sea of Japan following protests from China, North Korea's ally.

Border monitored

Amid the rising tension, military officials in Seoul said they were closely monitoring the North's military in border areas but had not detected any unusual activity in the run-up to the exercises, code-named Invincible Spirit.

The North's National Defence Commission denounced the war games as "nothing but outright provocations aimed to stifle the Democratic People's Republic of Korea [North Korea] by force of arms," the state-run Korean Central News Agency (KCNA) said.

"The army and people of the DPRK will start a retaliatory sacred war of their own style based on nuclear deterrent any time necessary in order to counter the US imperialists and the South Korean puppet forces deliberately pushing the situation to the brink of a war," it added.

The US responded by saying it was "not interested in a war of words with North Korea".

The four-day drill includes the aircraft carrier USS George Washington and some 200 fixed-wing aircraft, officials said.

The sinking of the Cheonan warship claimed the lives of 46 South Korean sailors.