South Korea has test-fired a new ballistic missile with a range of 500 km (310 miles) and will try to extend the range to 800 km so it can strike any site in North Korea, its defense ministry said on Friday, days after Pyongyang fired a mid-range missile, Reuters reported.
The new missiles are intended to counter the threat from North Korea's missile and nuclear programs, ministry spokesman Kim Min-seok said, but the move is likely to rattle the North, hit with U.N. sanctions for its own missile tests.
South Korea adopted a voluntary ban on developing ballistic missiles with a range of more than 300 km, under an agreement with the United States, but the allies agreed in 2012 to allow the South to develop 800 km-range missiles.
"We test-fired it, and we succeeded," Kim told a briefing, when asked if the military had recently conducted a 500-km missile test. "And we're going to make 800-km missiles."
The new missiles will be used to strike the North's weapons and military installations in the furthest part of the country from anywhere in the South if needed, he added.
The two Koreas are technically still at war, since the 1950-53 Korean War ended in a truce, rather than an armistice.
North Korea last week fired a mid-range ballistic Rodong missile that fell into the sea off its east coast after flying about 650 km and short of its maximum range, thought to be about 1,300 km, and enough to hit much of Japan.
North Korea this week fired more than 500 rounds of artillery into the sea off its west coast near a disputed maritime border in the latest sabre-rattling under its young leader Kim Jong Un, who has vowed to build nuclear weapons.
More than 100 rounds landed in the waters of the South, prompting it to fire back more than 300 rounds into the North's waters.
South Korea is also investigating two drones that crashed near its border with the North which it believes were flown by Pyongyang. One was recovered with evidence of having flown directly over the South's presidential palace.
North Korea's state media said last year that leader Kim Jong Un had supervised a drill of "super-precision" drone attacks on a simulated South Korean target.
Although the North has one of the world's largest standing armies, much of its equipment consists of antiquated Soviet-era designs. It has focused resources on developing nuclear and long-range missile programs.