U.S. Deputy Secretary of State Kurt Campbell speaks during a special roundtable with reporters at the Foreign Press Center in Washington, D.C., Dec. 19. Yonhap

The United States plans on having high-level in-person engagement with the administration of South Korea's Acting President Han Duck-soo, a top U.S. diplomat said Thursday, stressing that the Biden administration fully supports Han's interim role.

Deputy Secretary of State Kurt Campbell made the remarks amid concerns that the ongoing political turmoil in the aftermath of President Yoon Suk Yeol's botched martial law attempt and his subsequent impeachment would negatively affect bilateral cooperation between Seoul and Washington.

"I will not get into detail here, but we do plan on high-level engagement ... in-person engagement with the ROK appropriately in due course during the last weeks of the Biden administration," Campbell said during a roundtable with reporters at the Foreign Press Center. ROK is short for South Korea's official name, the Republic of Korea.

He added, "We are keeping every possible line of communication open not just with the interim government but (with) other actors in the crisis," he added.

Prime Minister Han took over as acting president immediately after the National Assembly voted to impeach Yoon on Saturday, suspending Yoon from his presidential duties until the Constitutional Court decides whether to reinstate or unseat him from office.

Campbell voiced the U.S.' support for Han, saying the acting president is "well known to us" while noting that Han served as South Korea's ambassador to the United States from 2009-2012.

"We fully support his interim role, and we will do what's best to continue to send the signal of deep engagement," he said.

The deputy secretary pointed out that even during a period of political uncertainty in Seoul, the U.S. has underscored the importance of a "steady" and "unshakable" commitment to the Seoul-Washington alliance.

"We have supported the constitutional steps that Korea has taken and we've expressed confidence in Korea to manage through this challenging period," he said.

Commenting on the possibility of North Korean provocations, Campbell underscored the U.S.' vigilance against it.

"We've sent the clearest possible message that no provocation from the DPRK on the Korean Peninsula during this period and that we are fully behind the ROK and vigilant (against) any provocations or (aggressive) steps," he said. "I think (there) should be no question about this."

DPRK stands for the official name of North Korea, the Democratic People's Republic of Korea.

Asked if he anticipates progress in diplomacy with Pyongyang under the second Trump administration, he struck a cautious note.

"I think (Trump) continues to be very focused on North Korea and (its leader) Kim Jong-un," he said, noting that "circumstances" have changed with the growing partnership between Moscow and Pyongyang.

"These are things that await the next administration. I cannot say whether he will be effective in this kind of diplomacy that he sought in both Singapore and Vietnam."

U.S. President Donald Trump, left, meets with North Korean leader Kim Jong-un at the North Korean side of the border at the village of Panmunjom in Demilitarized Zone on June 30, 2019. AP-Yonhap

He was referring to the in-person summit between Trump and Kim in Singapore in 2018 and Hanoi in 2019. Serious nuclear talks between the U.S. and the North have been stalled since the no-deal summit in Hanoi.

With Trump set to return to office next month, expectations have persisted that he would seek to rekindle his personal diplomacy with Kim.

But questions linger over whether Pyongyang would accede to any diplomatic feelers from Washington given that the North now relies on Russia for food, fuel, security guarantees and other forms of support. (Yonhap)