PYONGYANG, Dec 16 (AFP) - North Korea has tested a “high-thrust solid-fuel motor”, state media reported on Friday, as the isolated country continues efforts to develop a new strategic weapon and speeds up its nuclear and missile programmes.

The test, overseen by leader Kim Jong Un, took place on Thursday at North Korea’s Sohae Satellite Launching Ground, the official KCNA news agency said.

The static firing test proved the motor’s reliability and stability, providing a “guarantee for the development of another new-type strategic weapon system”, KCNA added.

Experts say the test appears aimed at developing a new solid-fuel intercontinental ballistic missile (ICBM) given the thrust of the engine, which North Korea said was “the first of its kind” in the country.

Pyongyang has been working to build more solid-fuel missiles, which are more stable and can be launched with almost no warning or preparation time.

“They can be used for surprise launches and show improved survivability against enemies’ attacks, meaning North Korea is accelerating its push to develop more powerful ICBMs and submarine-launched ballistic missiles,” said Lim Eul-chul, a professor of North Korean studies at Kyungnam University in South Korea.

“We cannot rule out the possibility of the North test-firing an ICBM with a new solid fuel rocket next year.”

Developing a solid-fuel ICBM was part of North Korea’s five military tasks rolled out at its key party meeting last year.

After overseeing the test, Kim said “another important problem in carrying out the five priority tasks” had been solved successfully, and expressed “expectation that another new-type strategic weapon would be made in the shortest span of time”, according to KCNA.

North Korea has conducted an unprecedented number of missile tests this year, including an ICBM capable of reaching the United States mainland, despite international bans and sanctions.

In March, Kim visited the Sohae site and called for expansion of the facility, which has been used to test various missile technologies, including static rocket engines and space launch vehicles.

A new report by the US-based Center for International and Strategic Studies (CSIS) said commercial satellite imagery showed construction of what appears to be a horizontal engine test stand, describing it as the “first of its kind” at the Sohae station.

The latest test took place as International Atomic Energy Agency chief Rafael Grossi visited Seoul for talks with South Korean officials and promised an all-out effort to stop North Korea’s nuclear programme.

During his meeting with Grossi, South Korean President Yoon Suk-yeol expressed concerns over North Korea’s “race” to advance its nuclear and missile programmes, calling for the United Nations agency’s cooperation to deter Pyongyang from making further provocations.

South Korean and US officials have said North Korea has completed preparations for a potential nuclear test, which would be the first since 2017.