South Korea and the United States are still struggling to narrow their differences over a proposed revision of a bilateral pact to allow Seoul to develop longer-range ballistic missiles, officials here said Monday.

The Korean government in Seoul denied a news report that the allies reached an agreement to extend the missile range stipulated in the deal to 550 km from the current 300 km, saying that negotiations are still ongoing.

The two countries have been in consultations for the past few months as North Korea has continuously sought to develop longer-range delivery vehicles and military nuclear technology.

“Working-level consultations are ongoing over the range extension, and we have yet to reach any agreement. We think it may be difficult to strike an agreement within this month,” a Seoul official told media on condition of anonymity.

“Seoul argues that the range should cover all areas of the peninsula while the U.S. holds a cautious stance. To narrow our differences, working-level negotiations will continue.”

A JoongAng Ilbo report said that the two sides had agreed to extend the range and will take steps to revise the pact after announcing the decision at a meeting of the countries’ foreign and defense ministers in Washington in mid-June.

But Defense Ministry spokesperson Kim Min-seok countered that by saying nothing has yet been decided.

“The two countries have held consultations over it, but there is nothing decided as of yet,” he said during a regular press briefing.

“The two share the view that the allies should draw up measures against North Korea’s long-range missiles and strengthen South Korea’s missile capabilities. We also have yet to finalize the agenda items for the allies’ ministers’ meeting later this month.”

Under a 2001 revision to the initial agreement, Seoul is banned from developing ballistic missiles with a range of more than 300 km. But it does not restrict the range of cruise missiles, which are much slower and easier to intercept.

It also stipulates that a payload must weigh no more than 500kg to block the development of nuclear warheads.

Seoul has apparently moved fast to revise the missile pact due to continuing threats from the North and considering the Washington government may have less flexibility over the sensitive issue ahead of its upcoming presidential election in November.

The U.S. has been reluctant over the range extension as it could undermine its initiatives of non-proliferation and arms control.

Seoul signed the first bilateral missile pact with Washington in 1979, despite the range limit of 180 km, on the condition the U.S. would assist with the South’s missile technology development.

After years of negotiations with the U.S. amid the North’s push for the development of advanced missile technology, the two allies agreed in 2001 to revise the original pact to extend the range to 300 km.

The longest-range North Korean ballistic missile, deployed since 2007, is the Musudan missile with a range of 3,000-4,000 km. This missile, in theory, brings Guam, a key U.S. strategic base in the Asia-Pacific region, within its range.

The longest-range North Korean missile under development is the Taepodong-2 missile, presumed to have a range of more than 6,700 km, enough to hit parts of Alaska, but still short of reaching the U.S. mainland. The missile’s tests have so far failed.

By Song Sang-ho (sshluck@heraldcorp.com)