Jeffrey Feltman, the UN under-secretary-general for political affairs, visited the reclusive nation between Tuesday and Friday, the first trip there by a top UN official in six years.
During his visit, he met with Ri Yong Ho, the North Korean minister for foreign affairs. Their meeting came at a particularly tense time -- a week after North Korea tested an advance long-range missile and South Korea conducted military drills with its ally, the United States.
Feltman stressed the need for relevant Security Council resolutions to be implemented, saying a diplomatic solution could be achieved through sincere dialogue.
In a statement to journalists, he said there's an "urgent need to prevent miscalculations and open channels to reduce the risks of conflict." He emphasized that the international community is alarmed by escalating tensions, and is committed to a peaceful resolution.
"Time is of the essence," he said.
Missiles and drills
North Korea remains technically at war with its neighbor South Korea after the Korean War ended in armistice but not peace in 1953.
Feltman's trip coincided with the annual Vigilante 18 military drill held by the US and South Korea, which the US Air Force says is designed to boost the "combat effectiveness" of the alliance.
North Korea's state media described the drills as "joint air war exercises targeting the DPRK," a reference to North Korea's official name, the Democratic People's Republic of Korea.
UN in North Korea
Feltman's visit to North Korea was a response to a "long standing invitation" from Pyongyang authorities for policy dialogue, the UN said ahead of the visit.
Feltman visited several UN projects in North Korea, including a pediatric hospital and Tuberculosis prevention institute.
China calls for peace
China has repeatedly called for a de-escalation of tensions on the Korean Peninsula, including a freeze in the North Korean nuclear program in exchange for the halt of United States and South Korean military drills.
China's official Xinhua news agency reported that Wang again raised the "suspension for suspension" proposal at an international relations conference Saturday.
"(Wang) noted that the situation on the Korean Peninsula is still deep in a vicious circle of demonstrating strength and confrontation, and the outlook is not optimistic," Xinhua said. "He said that all parties need to make efforts to ease the situation and bring the situation out of the 'black hole' of confrontation."
CNN's Kristina Sgueglia, Richard Roth and Joshua Berlinger contributed tot his report.