UNITED NATIONS (AP) — U.N. Secretary-General Ban Ki-moon on Monday called the execution of North Korean leader Kim Jong Un's uncle "very dramatic and surprising" and urged the country's neighbors not to take any "premature actions."

Ban, a former South Korean foreign minister, expressed hope that there will be no increase of tensions on the Korean peninsula following the execution of Jan Song Thaek, widely considered the No. 2 official in North Korea.

Ban, making his first public comments on the execution, also urged North Korea's leaders to work to denuclearize the Korean peninsula.

He stressed that North Korea must focus on improving the living conditions of its people and comply with Security Council resolutions, which it has long ignored.

In attempting to justify the execution, Kim destroyed the image of unity projected by North Korea's state-run media. Many analysts said the acknowledgement of dissension and dangerous instability in the government is an alarming prospect as Kim tries to revive a moribund economy while maintaining and advancing development of the country's nuclear arsenal.

Ban stressed that the United Nations has a longstanding and very clear position against the death penalty "under any circumstances."

He appealed to "all the parties concerned surrounding the Korean peninsula, while they must be diligently and carefully watching the development of situation, not to take any premature actions."

"The period ahead should be used to build confidence in the international community and to improve living conditions for the country's long-suffering people," Ban said. "I stand ready to offer my good offices."