North Korea says it had conducted yet another “crucial test” intending to use the results to strengthen its "strategic nuclear deterrent”, amid heightened tensions between Pyongyang and Washington, just ahead of a year-end deadline for the US to take a “new path” in its policy toward the country.

Axar.az reports citing PressYV that Pyongyang announced on Saturday that the test was conducted at the Sohae satellite launch site on Friday, the North’s official news agency KCNA reported.

“The research successes being registered by us in defense science one after another recently will be applied to further bolstering up the reliable strategic nuclear deterrent of the Democratic People’s Republic of Korea,” said KCNA, using the official name of the country.

It cited a spokesman for North Korea's Academy of Defense Science but did not specify what sort of testing was involved.

The test, the second at the facility in the last week, came ahead of a year-end deadline that the North’s leader, Kim Jong-un, set for Washington to take a “new path” and change its policy of insisting on Pyongyang’s unilateral denuclearization. Washington has rejected that timeline.