SEOUL, South Korea — The United States is open to talks on the possibility of South Korea developing ballistic missiles capable of striking all of North Korea, a South Korean Defense Ministry official said Tuesday.

A senior general at the U.S. command in Seoul told deputies to South Korean lawmakers last week that the allies can discuss the revision of a 2001 accord barring the South from developing missiles with a range of more than 186 miles (300 kilometers), the ministry official said.

He spoke on condition of anonymity, citing department policy, and refused to identify the U.S. general. The U.S. military command in Seoul said it could not immediately confirm the remarks.

South Korean politicians and experts have called for the improvement of their country's missile capability, citing North Korea's increasing missile and nuclear threats.

North Korea carried out its second nuclear test in May. On Saturday it test-fired a barrage of ballistic missiles into waters off its east coast, its biggest display of missile firepower in three years.

The North deploys hundreds of missiles that have all of South Korea and Japan within their striking range. In April, the North test-launched a long-range rocket believed capable of reaching Alaska.

The restriction on the South's missile capability was imposed due to concerns over a regional arms race. Under a 1979 accord with the U.S., South Korea had been barred from developing a missile with a range longer than 110 miles (180 kilometers) until 2001 when it was allowed to extend the range to 186 miles (300 kilometers).

In April, Prime Minister Han Seung-soo told the National Assembly it was time "to review" the restriction and discuss the matter with the U.S., days after the North test-fired a long-range rocket that flew over Japan and landed in the Pacific Ocean.

The missile accord still allows South Korea to develop a cruise missile without range restriction as long as its payload is under 1,100 pounds (500 kilograms). Cruise missiles can be intercepted more easily than ballistic missiles due to their slower speed, experts say.

Media reports say South Korea has been developing a cruise missile with a range of 930 miles (1,500 kilometers).

South Korea does not publicize the location of its missile facilities so it is difficult to know how much of North Korea is currently within range.

The distance from Seoul to the northernmost part of North Korea is about 400 miles (640 kilometers). The North Korean capital of Pyongyang is about 120 miles (200 kilometers) from Seoul.