SEOUL — South Korea has reached an agreement with the United States that lets Seoul more than double the range of its ballistic missiles to counter what it considers to be a growing threat from North Korea.
The revised agreement, which also tries to address Washington’s worries about a regional arms race, increases the payload the ballistic missiles can carry and allows South Korea to develop and deploy more powerful unmanned aircraft, or drones, that can carry reconnaissance equipment and weapons.
Under the revised guidelines, South Korea can deploy ballistic missiles with a range of up to about 500 miles, enough to reach any target in North Korea but not enough to be considered a threat to China or Japan.
The longer-range missile can be used only as long as the payload does not exceed about a half-ton. Seoul can load warheads weighing up to 2 tons on ballistic missiles with shorter ranges.
Until now, South Korea has been barred from deploying ballistic missiles with a range of more than 187 miles and a payload of more than a half-ton, a capacity Korean officials believed was not enough to protect their country from North Korea’s rapidly expanding nuclear and missile capabilities.
The South was also barred from deploying drones that can carry more than half a ton of weapons or equipment.
The new agreement allows South Korea to use drones that can carry up to 2½ tons of equipment and weapons. Drones have emerged as a powerful weapon in modern warfare and can be configured to fly higher than most conventional warplanes, making them harder to shoot down, according to military analysts. South Korea began deploying low-flying reconnaissance drones in 2002.
“The biggest objective for the revision is to prevent North Korea’s military provocations,” said Chun Yung Woo, the chief national security adviser for President Lee Myung Bak.
With an ability to deploy longer-range missiles or shorter-range missiles with heavier payloads, South Korea can significantly increase its deterrence capabilities, Shin Won Shik, a senior policy maker at the Defense Ministry, said during a news briefing.
North Korea has deployed a number of missiles, including some capable of hitting the US territory of Guam in addition to South Korea and Japan, Washington’s two main allies in Asia.
In April, North Korea launched its Unha-3 rocket. Although the long-range rocket failed to put a satellite into orbit, the United States and its allies condemned the launching as a cover for developing intercontinental ballistic missiles.
Possible objections from China and Japan were a major concern during the negotiations, and South Korean diplomats have spoken with counterparts in Beijing and Tokyo to clarify that the revised policy is not directed against them, officials said.
Shin said Washington and Seoul settled for limiting the maximum missile range to 500 miles to avoid “unnecessary misunderstanding and friction with neighboring countries.” He also reconfirmed that South Korea had no plan to join Washington’s missile defense program, which some analysts believe is intended to contain China’s military expansion.
The missile agreement takes place against the backdrop of Washington’s plans to increase its military presence in the Asia-Pacific region, which is a matter of concern in Beijing.
There was no immediate comment Sunday from leaders in China, which is North Korea’s closest ally. But Xinhua, the Chinese state news agency, suggested that the extension of the missile range “runs counter to a global arms control agreement known as the Missile Technology Control Regime.”
The so-called missile guidelines, required by Washington in 1979 because of its concern over a regional arms race and revised only once, 11 years ago, had become a major grievance among South Koreans.
Officials blamed the restriction for allowing their missile capacity to fall behind that of North Korea’s. Some key military installations in North Korea have been out of the range of South Korea’s ballistic missiles.
Washington has vowed to defend South Korea, but Seoul’s desire to improve its missile capabilities gained urgency as North Korea expanded its nuclear weapons program, tested long-range missiles, and carried out provocative military maneuvers, including an artillery barrage on a South Korean island in 2010. Lee appealed for a US concession when he met President Obama last year and again in March, South Korean officials said.