The Democratic People's Republic of Korea (DPRK) has conducted a "crucial significant" test at its satellite launch site, the Korean Central News Agency (KCNA) reported on Saturday.

The report said the test will further "bolster nuclear deterrence."

The unspecified test took place from 10:41 p.m. to 10:48 p.m. on Friday at the Sohae Satellite Launching Ground, better known as the Dongchang-ri site, KCNA said.

"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," KCNA reported.

The reported test came after the DPRK said it conducted an "important test" on December 7 at its Sohae satellite launch site.

After the test, Lee Sang-min, spokesperson for Seoul's unification ministry, said that both the DPRK and the U.S. are still willing to make progress through dialogue and the Republic of Korea (ROK) will take necessary actions to maintain dialogue momentum between the two sides.

The ROK spokesperson said the situation in the DPRK will be closely monitored.

Stephen Biegun, U.S. special representative for DPRK affairs, will make a three-day visit to the ROK, according to the Seoul ministry. 

The top U.S envoy for DPRK is set to arrive in Seoul on Sunday for meetings with ROK officials ahead of a year-end deadline set by Pyongyang for Washington to soften its approach to stalled denuclearization talks.