North Korea said it has tested a “high-thrust solid-fuel motor” to develop a new strategic weapon under leader Kim Jong Un’s guidance, state media reported on Friday.

The test conducted on Thursday at its Sohae Satellite Launching Ground proved the motor’s reliability and stability, providing a “guarantee for the development of another new-type strategic weapon system,” the official KCNA agency said.

Kim expressed “expectation that another new-type strategic weapon would be made in the shortest span of time,” according to KCNA.

The test comes as International Atomic Energy Agency chief Rafael Grossi is in Seoul for talks with South Korean officials during which he vowed an all-out effort to stop North Korea’s nuclear programme.

North Korea has conducted an unprecedented number of missile tests this year, including an intercontinental ballistic missile capable of reaching the U.S. mainland.