S Korea, US launch drills with aircraft carrier after North's missiles

South Korea and the United States have begun joint maritime exercises with a US aircraft, South Korea's military has said, a day after it scrambled fighter jets in reaction to an apparent North Korean bombing drill.

The maritime drills will take place in waters off South Korea's east coast on October 7-8, South Korea's Joint Chiefs of Staff said on Friday.

The drills come after North Korea launched a pair of ballistic missiles into the sea on Thursday, and later flew warplanes near the border with the South.

"We will continue to strengthen our operational capabilities and readiness to respond to any provocations by North Korea through joint drills with...the USS Ronald Reagan Carrier Strike Group," South Korea's Joint Chiefs of Staff said.

The US strike group already participated in trilateral missile defence exercises with warships from Japan and South Korea this week, prompted by a test on Tuesday in which North Korea launched a ballistic missile that over flew part of Japan.

Senior defence officials from Japan, South Korea and the United States discussed the latest developments in a call on Friday, condemning the North Korean launches and agreeing that recent trilateral maritime drills have improved their ability to respond to North Korea, South Korea's ministry of defence said in a statement.

READ MORE: North Korea fires two missiles as US redeploys aircraft carrier

'Clear message'

In a meeting with South Korean Defence Minister Lee Jong-sup, Admiral John Aquilino, the commander of the US Indo-Pacific Command, said North Korea's provocations seriously threaten the security of the region. He emphasised that his forces would actively support efforts to deter and respond to the North Korean threat, the ministry said in a separate statement.

Lee also held a meeting of senior officials to discuss the latest launches and to evaluate South Korea's "three-axis" defence system designed to counter North Korea's military threats, including war plans that call for preemptive strikes if necessary.

"He emphasised the need to deliver a clear message that nuclear and missile development will only create a more difficult situation for North Korea," the defence ministry said in a statement.

The rare bombing drill by at least eight North Korean fighter jets and four bombers on Thursday prompted the South to deploy 30 fighters.

The warplanes swarmed each side of the heavily fortified border amid rising tensions over a string of missile tests by Pyongyang.

North Korea on Thursday condemned the United States for repositioning the aircraft carrier near the peninsula, saying it posed a serious threat to the stability of the situation.

READ MORE: North Korea fires 'ballistic missile,' prompts evacuation alert in Japan