UNITED NATIONS — Secretary-General Ban Ki-moon believes any dialogue between the United States and North Korea should focus on the goal of denuclearizing the Korean peninsula, a U.N. spokesman said Monday.

U.N. deputy spokesman Eduardo del Buey said that Ban also believes inter-Korean dialogue is key to defusing tensions and ensuring peace on the peninsula.

Ban's spokesman was asked to comment on North Korea's surprise proposal Sunday to hold nuclear and security talks with the United States without preconditions. The proposal followed months of rising tensions and anti-American rhetoric by North Korea and last week's collapse of proposed high-level talks between North and South Korea amid bickering over who would lead the two delegations.

Ban, a former South Korean foreign minister who has closely watched developments on the Korean peninsula, was heading to Beijing on Monday for high-level talks with China's new leaders, including President Xi Jinping.

The secretary-general said that tensions on the Korean peninsula were among the "many matters of common concern" that he plans to raise with Xi and other Chinese leaders.

In a unanimous resolution drafted by the U.S. and China, which is North Korea's main benefactor, the U.N. Security Council in March imposed a fourth round of sanctions against North Korea following its underground nuclear test on Feb. 12. Immediately afterward, Beijing called for defusing tensions and restarting negotiations on North Korea's nuclear program, but the country's new young leader, Kim Jong Un, responded with war-like rhetoric and new threats against the United States.

In April, Ban said North Korea's nuclear test, threats and provocative actions had strengthened the international consensus that the reclusive communist nation will not be accepted as a nuclear weapon state. North Korea is thought to have a handful of crude nuclear bombs.

Ban urged all countries in the region to step up diplomatic efforts to reduce tensions and avoid "any miscalculation or misjudgment" that could lead to "uncontrollable" violence.

Del Buey said Monday that the secretary-general had "noted" the North's proposal of talks with the United States.

"He has consistently stated that the parties should resolve their differences through dialogue, and for any dialogue to be meaningful it should be firmly anchored in the common goal of the denuclearization of the Korean peninsula," del Buey said.

South and North Korea agreed in a 1992 joint declaration not to produce, test or use nuclear weapons. North Korea has since conducted three nuclear tests.

"In the same vein," del Buey said, "the secretary-general stresses the importance of inter-Korean dialogue which is key to defusing tensions on the Korean peninsula and ensuring durable peace and security in the region."