Pyongyang, North Korea - North Korea said on Thursday it had tested a "cutting-edge" new weapon system using hypersonic missiles aimed at bolstering its defenses against Pyongyang's foes.

The launch was detected by Seoul's military on Wednesday and was Pyongyang's first of its kind in months.

It came a week before world leaders, including US President Donald Trump, are set to descend on South Korea for a major regional summit.

Top military official Pak Jong Chon declared the "new cutting-edge weapon system is a clear proof of steadily upgrading self-defensive technical capabilities of the DPRK," state news agency KCNA said.

KCNA said the test was aimed at enhancing the "sustainability and effectiveness of strategic deterrence against potential enemies."

North Korean leader Kim Jong-un was not reported to have attended the launch.

State media said the two "hypersonic projectiles" had been launched south of the capital Pyongyang and had hit a target in the country's northeast.

Images shared by KCNA showed a missile flying through the air, before hitting a target and exploding in a hail of black dirt and smoke.

Hypersonic missiles travel at more than five times the speed of sound and can maneuver mid-flight, making them harder to track and intercept.

They have been deployed to deadly effect this year on cities in Ukraine by Russia, with whom North Korea has deepened ties in recent years, and by Iran against Israel.

North Korean media did not share details of the new missiles' range, trajectory angle or speed.

And Kim's absence from the launch may indicate Pyongyang was seeking to "tone down" its impact, Yang Moo-jin, former president of the University of North Korean Studies in Seoul, told AFP.

"However, given its range, the hypersonic missile is clearly aimed at the South," added Yang, noting the timing of the launch just days before the APEC summit.