US National Security Advisor Robert O'Brien said Monday that the decadeslong relationship between Seoul and Washington will remain strong "whoever" is inaugurated as president in January.

In a telephone conference with reporters during his visit to Manila, O'Brien also voiced hope that North Korean leader Kim Jong-un will eventually live up to his denuclearization commitment, amid worries Pyongyang could undertake provocations to test the incoming Joe Biden administration.

"Whatever happens on January 20, whoever the president is ...

I'm convinced that the relationship, which has endured for 70 years, will continue to endure and will be a strong partnership," O'Brien said.

"I think that sends a message to the DPRK," he added, referring to the North's official name, Democratic People's Republic of Korea.

The security advisor also said that Washington has been "gratified" as the North has not conducted any long-range ballistic missile or nuclear tests since U.S. President Donald Trump and Kim held a summit in 2018.

"So, we think that personal diplomacy between President Trump and Chairman Kim has led to that result," he said.

He then made a call for Kim to stick to his commitment to denuclearize.

"We are hopeful that Chairman Kim (Jong-un) will eventually live up to North Korea's commitment to denuclearize the peninsula, and we think that will be a tremendous step not just for South Korea and America, but for North Korea," he said.

Noting Vietnam -- the first leg of his Asia trip this week -- has made "tremendous strides" in reference to its economic achievements and enhanced ties with the U.S, O'Brien stressed that Vietnam can be an example of "what could take place in North Korea."  (Yonhap)