South Korea's top nuclear envoy, Cho Tae-yong, urged North Korea Tuesday to take "actions" to assure that it is serious about denuclearization as he began a three-day trip to Washington for consultations on ways to deal with Pyongyang.

"North Korea should show its will for a real denuclearization through actions," Cho, who serves as South Korea's special representative for Korean Peninsula peace and security affairs, told reporters upon arriving.

His trip comes amid renewed efforts to revive negotiations on North Korea's nuclear program following months of sharp military tensions on the peninsula.

 Pyongyang is apparently on a charm offensive but Seoul and Washington question its intentions.

"North Korea recently proposed dialogue but what is important is to achieve the substantial denuclearization of North Korea, not to just resume talks," Cho stressed.

Cho met with his American counterpart, Glyn Davies, later in the day to assess the current situation and discuss next steps.

On Wednesday they plan to hold a tripartite meeting with Shinsuke Sugiyama, Japan's top delegate to the six-way talks on North Korea's nuclear program. The talks, also involving China and Russia, have not been held for more than four years.

It is Cho's first overseas trip since taking up the post in late May. It will also mark the first time that the three countries have held a high-level trilateral meeting on North Korea in six months.

Davies is expected to brief his counterparts about the results of summit talks between President Barack Obama of the U.S. and President Xi Jinping of China held in California earlier this month.

In a press release, the State Department said, "These discussions reflect the close cooperation among our three countries and our common interest in ensuring peace and stability on the Korean Peninsula."

Meanwhile, North Korea's Vice Foreign Minister, Kim Kye-gwan, is scheduled to visit Beijing later this week.

South Korean envoy Cho will also travel to Beijing over the weekend after his trip to Washington.

Both Kim and Cho are expected to meet China's point man on North Korea, Wu Dawei, and other senior Chinese officials.

South Korean President Park Geun-hye plans to visit China later this month for a summit with Xi, which is expected to focus on the North Korea issue and ways to boost Seoul-Beijing ties. (Yonhap News)