Paul Wolfowitz, former United States deputy secretary of defense, expressed skepticism on Wednesday over North Korea's seriousness about its denuclearization, citing the track record of the North making agreements only to break them later.

Wolfowitz, known for his hawkish views on the North while serving as the deputy secretary from 2001-2005, added that it would be necessary to intensify sanctions if the planned South Korea and the US summits with North Korea do not produce satisfactory results.

"Count me as skeptical. We heard announcements like that before," he said during a press meeting in Seoul in response to a question as to how serious the North would be about its denuclearization following Pyongyang's announcement on Saturday that it would stop nuclear tests and shut down a nuclear test site.

"This one is different in one respect as far as I am aware. I think it's the first time that they said that they are doing this ... kind of freeze. But that's because, we (North Korea) have already finished the program and are ready to go. I mean that's not exactly encouraging," he added.

South Korea and the US are currently preparing to hold their respective summits with North Korea. The leaders of the two Koreas are set to meet on the southern side of the truce village of Panmunjom on Friday.

Wolfowitz voiced deep doubt about the possibility that the North will eventually give up its nuclear weapons, conjuring up the "dubious" track record of North Korea.

"I have great doubt whether the North Korean regime is gonna give up the ultimate weapon after it has gone through such great efforts to acquire it," he said. "We have a very dubious record from the past in terms of North Korea making agreements which they don't take seriously."

He called for everybody to be careful and prepared for any unsatisfactory results coming from the back-to-back summits with North Korea, calling for more sanctions to be readily imposed on the North.

"I think it would be a big mistake to relax sanctions on North Korea simply for very vague promises about doing something in the future," he noted.

He still added that despite all the skepticism he has expressed, he hopes, "We are entering a new era in relations with North Korea."

Wolfowitz said that the world is not focused only on the nuclear problem in North Korea as was the case with Iran where there were so many other issues, such as conventional weapons and violations of human rights.

"There is a certain lesson to be drawn from nuclear negotiations with Iran where I believe we got so focused on nuclear weapons that we forgot about everything else, including conventional weapons, including fundamental violations of human rights in Iran," he said.

"I believe we have been doing the same thing in North Korea now for 25 years. There are other issues in North Korea," he added.(Yonhap)