SEOUL, South Korea - North Korea threatened Monday to bolster its nuclear capability in a new -- though unspecified -- way to cope with what it says is a hostile U.S. policy and military threats amid tensions over the deadly sinking of a South Korean warship.
The North's military also accused the U.S. and South Korea of bringing heavy weapons to the village of Panmunjom -- which lies along the heavily militarized border between the Koreas -- and vowed to take "strong military countermeasures" if they aren't withdrawn.
Neither Washington nor Seoul had immediate comment on the accusation, though both Koreas have increased military preparedness in the wake of the sinking of the warship Cheonan. An international investigation concluded last month that North Korea torpedoed the vessel near the tense Korean sea border.
North Korea flatly denies the allegation and has warned any punishment would trigger war. Forty-six South Korean sailors died in the sinking.
"The recent disturbing development on the Korean peninsula underscores the need for (North Korea) to bolster its nuclear deterrent in a newly developed way to cope with the U.S. persistent hostile policy toward (the North) and military threat toward it," the North's Foreign Ministry said in a statement.
The statement, carried by the official Korean Central News Agency, did not elaborate on how North Korea would strengthen its nuclear capability. The North is known to have a plutonium-based atomic program and has carried out two underground nuclear explosions, one in 2006 and the other in 2009. Pyongyang is believed to have enough weaponized plutonium for at least a half-dozen weapons.
Analysts said Monday's threat likely referred to recent statements from the North that have trumpeted new nuclear programs.
Last year, Pyongynang said it was in the final stages of enriching uranium, which could provide an easier way to make nuclear bombs. Also, North Korea said in May that it had succeeded in creating a nuclear fusion reaction -- a key technology necessary to manufacture a hydrogen bomb -- though South Korean experts doubt the claim.
"North Korea is applying pressure on the U.S. by saying it can have additional nuclear capability," said Koh Yu-hwan at Seoul's Dongguk University.
North Korea cites the threat of a nuclear attack from the U.S. as the main reason behind its drive to build atomic weapons, though the U.S. has repeatedly said it has no intention of launching an attack.
The North's warning came after top world leaders at a G8 meeting near Toronto over the weekend criticized its nuclear program. The leaders also condemned the attack that led to the sinking of the Cheonan, citing an independent report that found North Korea was responsible.
Also Monday, the North's military said, "the fully armed U.S. imperialist aggression troops and the South Korean puppet army" deployed heavy weapons to Panmunjom village.
It was "an indication that they are set to perpetrate a military provocation (at) any moment," the North's military said in a protest message sent to the U.S. command in Seoul on Monday, according to a separate KCNA dispatch.
The U.S. military said it was checking the North Korean statement. South Korea's Joint Chiefs of Staff said it cannot confirm North Korea's claim that weapons were brought into Panmunjom.
Despite the tensions, Seoul officials and experts have said major armed clashes are unlikely. Seoul's Defense Ministry said Monday that there has been no unusual activity by North Korean troops in border areas.
The 1950-53 Korean War ended in an armistice rather than a peace treaty. The United States stations about 28,500 troops in South Korea as a deterrent against the North.
The American-run UN Command -- which oversees the armistice -- said in a statement Monday it has proposed military talks with North Korea to discuss the warship sinking but the North declined it. On Sunday, Pyongyang accused the U.S. of trying to meddle in inter-Korean affairs under the name of the UN.
