Victor Cha, a former senior adviser on North Korea for the George W. Bush administration, said North Korea could conduct a nuclear test ahead of President Yoon Suk Yeol's US visit next week to renew the allies' commitment to regional security.

"When there is no diplomacy between the US and DPRK and we have military exercises (against the regime), North Korea does a lot of activities and a lot of negative activities," Cha, senior vice president and Korea chair at the Center for Strategic and International Studies, said in an interview with The Korea Herald.

“The fact that there is a state visit a week from now and there is no diplomacy and we’re and we did these big exercises ... My guess is that that will incentivize them even more, to do even more things. So maybe a seventh nuclear test or something of that nature in response to the state visit."

As Yoon prepares to visit the US next week, joint military exercises involving South Korea, the US and Japan have continued. On Monday, the three nations conducted ballistic missile defense drills in an effort to curb and respond to North Korea's nuclear and missile threats, following a joint exercise between the US and Japan over the East Sea the previous week.

As Cha noted, these missile drills have been underway as there has been a lack of progress in talks between the US and North Korea since the fallout of the 2019 North Korea-US Hanoi summit.

North Korea's testing of missiles and nuclear capabilities is no longer solely aimed at “gaining attention” from the United States, Cha said.

“They are doing two things. One is they're testing new technology. And two is that they are not doing testing. They're exercising. They're actually exercising capabilities,” he said.

North Korea is prepared to conduct a nuclear test at any time, according to South Korean Defense Minister Lee Jong-sup earlier this month, and his ministry is closely monitoring the situation. Army Gen. Paul LaCamera, commander of US Forces Korea said on Tuesday the Kim regime has developed capabilities that reach beyond Seoul, Tokyo and Washington.

When asked about the solution to halt North Korea's activities, Cha said there is currently "no good answer" and the situation is "not very optimistic."

"North Korea is not interested in diplomacy. They are not responding to any efforts at diplomacy by others. The Biden administration has reached out to North Korea a number of times, but there is no response from North Korea," he said.

“There is absolutely no response.”

Nongovernmental organizations and European Union embassies are also not in North Korea.

At present, China is the only country that has been granted access to North Korea, but both China and Russia are "not entirely unhelpful" in dealing with the situation, he said.

"When I was doing six party talks, China saw North Korean provocations as bad for China," he said.

"When North Korea did a missile test, they thought that was bad for China, and they tried very hard to stop that."

Now, China sees North Korean provocations as putting more pressure on the United States and demonstrating to the US the cost of their strategic competition with China, he said.

And after the 2019 Hanoi Summit ended in embarrassment for North Korean leader Kim Jong-un, no one in the North Korean government would be willing to risk their lives in suggesting that they should try diplomacy again, he added.

Sanctions have also proven ineffective.

“We can continue to try sanctions but North Korea has sanctioned itself harder than any sanctions that we could have thought of because of COVID-19,” he said.

Amidst the growing geopolitical uncertainty, tensions have escalated as North Korea continues to provoke with a series of missile launches. The regime has fired nine missiles in the past four months, in addition to firing at least 70 ballistic missiles over 30 rounds, including eight intercontinental ballistic missiles, last year. There have been reports that the regime is preparing for its seventh nuclear test, which Seoul predicts could occur once all the physical preparations are complete.

Given South Korea's rising concerns over North Korea's persistent provocations, the discussions about strengthening extended deterrence have intensified.

In a poll released by Gallup Korea in January, 76.6 percent of the respondents said they support South Korea's independent nuclear development. It is 17 percentage points higher than 60 percent of the public opinion in favor of possessing nuclear weapons in a poll released by the same agency in 2017.

Cha said he does not endorse the recent proposal of nuclear sharing, citing the high risks of involving domestic political processes. He also contends that it would not improve deterrence capabilities, but instead create further uncertainty, given that tactical nuclear weapons in South Korea would become a prime target for North Korea.

While expressing confidence in the US extended deterrence capability, Cha, however, emphasized the need for further assurances for its ally.

“Extended deterrence is about two things. It’s about reassurance and capabilities,” he said.

“There is no question on the capability side, but it is really on the political reassurance side. It is harder.”

He said the challenge lies in finding the right political reassurances and steps to address the situation effectively, and believes both allies are actively working toward that goal.

While it is unclear what specific announcement will be made at the upcoming summit, he believes that the two countries are focused on finding the appropriate “political reassurances” and steps to address the issue at hand.

"Clearly the most pressing issue in terms of security is North Korea and extended deterrence. So I expect that they will spend a lot of time discussing that," he said.

"President (Joe) Biden will try to be as reassuring as possible in terms of the strength of the US commitment. I think they'll emphasize how there's no space between how Seoul and Washington think about this issue."

This is the third installment of a series of interviews, features and analyses on the South Korea-US alliance -- a 70-year-old partnership that has been instrumental in shaping the Korean Peninsula's contemporary history from the ruins of the 1950-53 Korean War, and which continues to serve as a stalwart pillar of regional security -- as well as its challenges ahead. -- Ed.