North Korea should end its nuclear activities and provocative acts if it hopes to see the resumption of long-stalled talks aimed at convincing Pyongyang to give up its nuclear weapons program, the outgoing U.S. ambassador said Sunday.

Ambassador Sung Kim said that Washington remains open to dialogue with the North, but it will not rush into any serious process with the communist country unless the North takes “concrete steps” in showing its commitment toward denuclearization.

“Obviously it is unfortunate that we have not been able to make any progress on the nuclear issue ... But I think that it would be a mistake for us to rush into any process or any negotiation without some confidence that North Korea would be a much more committed partner this time,” Kim said in an interview with Yonhap.

Kim, a career diplomat with expertise on the North Korean nuclear issue, has served as the first Korean-born U.S. ambassador to South Korea since November 2011. With his stint in Seoul nearing an end, there is growing speculation that Kim may be named as the top U.S. nuclear envoy, replacing Glyn Davies.

The six-party talks aimed at denuclearizing North Korea, which involve the two Koreas, the United States, China, Russia and Japan, have been dormant since late 2008 as the North walked away from the negotiation table.

Since then, the nuclear impasses have been drawn out amid concerns that the North has been advancing its nuclear capabilities. Pyongyang has threatened to conduct a fourth nuclear test while stepping up its provocations in recent weeks by launching short-range missiles and artillery shells.

Since its third nuclear test last year, North Korea has repeatedly expressed its intention to return to the six-party forum “without preconditions.” The North also conducted nuclear tests in 2006 and 2009.

South Korea and the U.S. have said that Pyongyang must first show its sincerity toward denuclearization before such talks can resume. But China, a long-time ally of North Korea, has been urging Seoul and Washington to lower their bar for the talks.

Kim said that the U.S. government remains “open to dialogue and engagement diplomacy with North Korea,” but stressed that what it is looking for is dialogue that can produce “meaningful progress” on the nuclear issue.

He said that what Washington has been discussing with Seoul and other partners in the region is “relatively modest steps” that the North could take.

“We want to see some concrete steps by North Korea to demonstrate their commitment,” he noted.

Kim refrained from commenting on what concrete steps mean, but he viewed the cessation of provocative actions by North Korea as “an obvious condition” for the resumption of any talks.

“It will be difficult for us to enter into any serious negotiation while North Korea is continuing their nuclear activities. So we will expect that if we are to resume the process, they would shut down or suspend all nuclear activities,” he said.

Touching on recent developments in relations between South Korea and China, the U.S. envoy dismissed views that the improving ties between the two countries could hamper Seoul’s alliance with the U.S. or its trilateral coordination with Washington and Japan in curbing Pyongyang’s nuclear ambitions.

South Korean President Park Geun-hye and her Chinese counterpart, Xi Jinping, held a summit in early July in Seoul, vowing to strengthen their strategic partnership. It marked the first time that a sitting Chinese president visited Seoul before traveling to North Korea.

“In fact, I think China’s interaction with the Republic of Korea will help China move in a positive direction as it continues to rise,” said Kim, using the full name of South Korea. “I am not at all worried that somehow improving relations between Korea and China will weaken or undermine the U.S.-Korea alliance.”

He said that it would be “a mistake to view these dynamics as simple and a zero-sum equation.”

“More broadly speaking, positive and constructive relations between China and Korea helps regional peace and stability, which of course is in the U.S. interest as well,” he added.

Speaking about the issue of so-called “comfort women,” Kim said that Japan’s sexual enslavement of Korean women during World War II is “a horrible human rights violation.”

Japan has increasingly unnerved its neighboring countries by making attempts to deny its wartime atrocities. Tokyo has revealed the results of a recent review of its key 1993 statement acknowledging the Japanese army’s coercion of Korean and other Asian women into sexual slavery.

Japan’s review of the so-called “Kono Statement” has invited strong criticism from South Korea as Japan indicated that it was the outcome of political compromise between Seoul and Tokyo.

Kim expressed hopes that the two countries could work on addressing the comfort women issue to the satisfaction of the remaining 54 victims.

“As a friend and as a close ally, we have strong interests in how this issue is handled. We will continue to encourage our friends to try to find acceptable solutions to this very painful issue,” he added.

Looking back on his time in Seoul, Kim said it has been “an amazing experience” for him to serve as the first Korean-American envoy to South Korea.

The one thing that he regrets about his stint is that he has not had many opportunities to interact more with the public as his job is so busy and demanding, he said.

“That’s just a very small complaint,” Kim added.

The ambassador noted that his experience as the U.S. envoy to Seoul will be the highlight of his career, something that he will cherish for the rest of his life.

“I hope that I can come back someday in a different capacity to continue to help build our strong relationship,” Kim added.

Kim was born in South Korea and moved to the U.S. in the 1970s before obtaining U.S. citizenship in 1980. He has spent much of his career working on the Seoul-Washington alliance and the North Korean nuclear crisis.

Mark Lippert, U.S. Defense Secretary Chuck Hagel’s chief of staff, has been named as Washington’s choice as Kim’s successor. (Yonhap)