Cho Tae-yong, South Korea's special representative for Korean Peninsula peace and security affairs, made the remarks as he left for Washington for a trilateral meeting with his American and Japanese counterparts -- Glyn Davies and Shinsuke Sugiyama.
The trip by Cho to the U.S. came two days after North Korea offered talks with Washington aimed at easing tensions and denuclearizing the Korean Peninsula. Cho will also visit Beijing later this week.
"At this point, it is important for relevant parties to rebuild trust so that progress can be made toward the goal of denuclearizing North Korea, rather than talks for talks' sake," Cho told Yonhap News Agency by telephone.
The trilateral meeting in Washington will be held on Wednesday and Cho will fly to Beijing on Friday before returning home.
Cho's trip to Washington and Beijing coincides with a visit by North Korea's chief nuclear negotiator, Kim Kye-gwan, to Beijing on Wednesday.
Kim plans to meet with Chinese Vice Foreign Minister Zhang Yesui in Beijing for a "strategic dialogue," China's foreign ministry spokesperson Hua Chunying said.
Asked about a possible encounter with Kim in Beijing, Cho replied that he has "no plan" to meet with him.
After months of provocations, including a third nuclear test and bellicose threats against South Korea and the U.S., North Korea has appeared to shift to dialogue in recent weeks. Pyongyang had proposed talks with Seoul, but the proposed inter-Korean dialogue collapsed last week due to a difference over the seniority level of chief representatives.
On Sunday, North Korea issued a surprise overture of talks to the U.S., but insisted that there should be no preconditions if such a dialogue takes place -- a condition Washington would never accept.
Officials in Seoul and Washington have reacted skeptically to the North's latest overture, saying Pyongyang must demonstrate its sincerity for talks through action, not words.
The six-party talks aimed at persuading the North to give up its nuclear ambitions has been stalled since late 2008. The multilateral forum involved the two Koreas, the U.S., China, Russia and Japan.
South Korea and the U.S. have stressed that North Korea must comply with U.N. Security Council resolutions and abide by international obligations for the resumption of the six-party talks.
In a report to the National Assembly on Tuesday, Seoul's foreign ministry played down the North's proposal of talks to the U.S. as its typical "peace offensive."
"The North's dialogue offer to the U.S. has been already expected and fits its typical tactic of a peace offensive," the report said, adding the ministry is "doubtful of the North's willingness for denuclearization."
Earlier in the day, the North's veteran nuclear envoy Kim arrived in Beijing for the Wednesday talks with Chinese officials.
Kim is the second senior North Korean official to visit China after the North Korean leader's special envoy, Vice Marshal Choe Ryong-hae, met Chinese President Xi Jinping late last month.