SEOUL, South Korea — South Korea and the United States launched a joint naval exercise involving a US nuclear submarine Monday, as tensions rise on the Korean peninsula ahead of an expected nuclear test by North Korea.
A defense ministry spokesman confirmed the three-day drill — condemned as a "warmongering" exercise by North Korea — was underway in the East Sea (Sea of Japan) off the southeastern South Korean port of Pohang.
Although South Korean military officials stressed the drill was scheduled before the North threatened to detonate its third nuclear device, the presence of the submarine has been seen as a warning to Pyongyang.
"The joint naval exercise is without a doubt an attempt to deter North Korea from conducting its nuclear test," said GlobalPost senior correspondent Geoffrey Cain.
Cain cited the presence of the USS San Francisco, a 6800-ton nuclear submarine armed with Tomahawk cruise missiles, at the naval exercises.
"The exercise includes at-sea operating training, detecting and tracking a submarine, anti-air and anti-ship live fire training and anti-missile training," the Yonhap news agency quoted one military official as saying.
The drill comes as the North has ramped up daily threats of a nuclear test in response to expanded UN sanctions imposed after its long-range rocket launch in December.
On Sunday, state media reported that the North's young leader, Kim Jong Un, had chaired a high-level meeting to discuss a "great turn" in bolstering military capability and issue "important" guidelines to top officials.
Although the report made no specific mention of a nuclear test, many observers in South Korea saw the meeting amounting to an official go-ahead for a detonation.
Recent satellite imagery has confirmed activity at the northeastern nuclear test site at Punggye-ri, with the North covering the entrance to a test tunnel in an apparent attempt to external monitoring.
"They've concluded that North Korea could, therefore, be getting ready to detonate two bombs at the same time or back-to-back, perhaps to demonstrate their power," said GlobalPost's Cain from Seoul.
If the allegation turns out true, it would be significant. This signifies that the pariah state is not using highly enriched uranium, as was discovered early last year, but that it's gone so far to produce two pretty sophisticated, expensive bombs when you consider its level of poverty.
Some predict the test will come before the Lunar New Year on Feb. 10, while others suggest it will be timed to coincide with the birthday of Kim Jong Un's father and late leader Kim Jong Il on Feb. 16.
South Korean President Lee Myung-Bak urged officials to "stand well prepared" for any test after a meeting Sunday with his top security advisers, and the defense ministry said Monday that the North had completed all technical preparations.
"The only thing left to make is a political judgement," ministry spokesman Kim Min-Seok said, calling on Pyongyang to show restraint.
Joint exercises are common in South Korea as a show of force to Pyongyang, the most famous perhaps being the Team Spirit exercises held between the US and South Korea from 1976 to 1993. The games were canceled in hopes of improving relations.
"But as always, we've learned that the North Korean regime will do whatever it can to cling to power, whether or not the outside world chooses to engage it," said Cain.
Over the past week Pyongyang has issued a series of daily warnings threatening an aggressive response to the latest UN sanctions, including a promise Saturday of the "toughest retaliation."
The North insists that its December rocket launch was a purely scientific mission aimed at putting a satellite in orbit.
But most of the world viewed it as a disguised ballistic missile test that violated UN resolutions triggered by the North's previous nuclear tests in 2006 and 2009.
Seoul's top nuclear envoy left for Beijing on Sunday to meet with his Chinese counterpart in an apparent last ditch effort to avert another test.
The North's only major ally and economic lifeline, China is seen as the one country with real leverage over the regime in Pyongyang.
Beijing also chairs the stalled six-nation nuclear disarmament forum on the North, which involves the two Koreas, Japan, the US and Russia.
The North withdrew from the aid-for-denuclearization talks in April 2009 and staged its second atomic test a month later.
Geoffrey Cain contributed to this report from Seoul.