Washington ? Rejecting U.S. disarmament demands, North Korea said Thursday it would prove to the world that it possesses nuclear weapons by carrying out a nuclear test, a U.S. government official said.

At a six-nation meeting in China that included the United States, North Korean Deputy Foreign Minister Kim Yong Il also said, according to the U.S. official, that his country had the means to deliver nuclear weapons, an apparent reference to its highly developed missile program.

The State Department declined comment on the deliberations in Beijing except to reiterate that the U.S. goal at the conference was to focus on “the complete, verifiable and irreversible elimination” of North Korea’s nuclear weapons program.

Wie Sung-rak, director-general of the South Korean Foreign Ministry’s North American Affairs Bureau, injected a positive note, saying in Beijing that another round of talks probably will begin after the current round ends today. Efforts to confirm Wie’s statement with U.S. officials were unsuccessful.

But North Korea said today that prospects for another round of nuclear talks were in jeopardy because of inflexibility on the part of U.S. negotiators, a South Korean news agency reported.

North Korea had confirmed privately to U.S. officials in April during talks in China that it possessed nuclear weapons, but Kim’s statement Thursday is believed to have been its first such acknowledgment in a formal setting.

Present for Kim’s presentation at a guest house in western Beijing were Assistant Secretary of State James A. Kelly and representatives from China, South Korea, Japan and Russia.

There was speculation here that North Korea could carry out a nuclear test on Sept. 9, the anniversary of the formation of the Democratic People’s Republic of Korea.