MOSCOW, October 31 (IslamOnline & News Agencies) - North Korea is entitled to develop nuclear and other weapons of mass destruction because of a U.S. threat to its sovereignty, Pyongyang's Ambassador to Moscow said Thursday, October 31, in the first firm defense of its clandestine military program.

"We unambiguously told the U.S. presidential special envoy that, facing a growing nuclear threat from the U.S., we have the right to possess not only nuclear, but even more powerful weapons in order to defend our sovereignty and the right to survive," Pak Hui Chun said.

"U.S. special envoy James Kelly absolutely groundlessly accused us of violating the U.N.-North Korea agreement by speeding up the implementation of a uranium-enrichment program to obtain nuclear weapons," Pak said in reference to the U.S. envoy's visit to Pyongyang earlier this month, Agence France-Presse (AFP) reported.

The Ambassador further dismissed U.S. allegations that North Korea rejected a 1994 framework agreement in which Pyongyang agreed to halt development of its nuclear program, the Interfax news agency reported.

The United States "had failed to present any proof" that North Korea is enriching its uranium to weapons-grade, RIA Novosti quoted Pak as saying.

The United States says that North Korea admitted to pursuing a nuclear program during October talks with U.S. envoy Kelly.

After holding talks with Russian officials last week, U.S. under Secretary of State for arms control and international security John Bolton said Moscow shared U.S. concerns over North Korea's "flagrant violation" of its treaty commitments.

However, Russian Deputy Foreign Minister Alexander Losyukov said Monday, October 28, that Moscow has seen no solid evidence that North Korea has a nuclear weapons program.

Russia has sought clarification following Pyongyang's apparent admission, according to Washington, that it had a covert nuclear weapons program, Losyukov was quoted as saying by the RIA Novosti news agency.

Bolton, who early last week held talks in Moscow with Russian officials, presented "the U.S. version," said Losyukov.

"We also received information from the North Korean side just before Pyongyang's official statement on this issue," he said.

"We did not receive any documentary evidence about the existence of such a program either from the U.S. or the North Korean side," the Russian diplomat said. "The situation surrounding this question remains unclear."

Under a 1994 nuclear pact with the United States, North Korea agreed to freeze its nuclear weapons program in exchange for two light-water reactors as well as fuel oil.

Russia has often attempted to act as a mediator between Pyongyang and Washington, which has branded North Korea as a member of its "axis of evil."

In a separate related development, South Korea's intelligence agency chief told lawmakers Monday that North Korea possesses some 4,000 tons of biochemical weapons and has built as many as three crude nuclear weapons.

In testimony to the parliament's Intelligence Committee, Shin Kun, director of the National Intelligence Service, said the North was capable of producing some 4,500 tons of weapons annually.

Pyongyang began its biochemical weapons program about four decades ago.

"The North is believed to have a stockpile of between 2,500-4,000 tons of biochemical weapons," an opposition Grand National Party (GNP) lawmaker, Lee Yoon-Sung, quoted Shin as saying Tuesday, October 29.

"We are unable to judge how powerful those biochemical weapons are as we have yet to confirm the accuracy of their delivery systems and whether the North has made those weapons compact enough to deliver."

Echoing what U.S. officials said of the North's nuclear development program, Shin said Pyongyang could already own as many as three crude nuclear weapons.

The weapons would have been built using some seven to 22 kilograms (15 to 49 pounds) of plutonium the North is believed to have extracted before it opened nuclear facilities to International Atomic Energy Agency (IAEA) inspections in 1992.

"We don't have any information on how much enriched uranium the North might have. South Korea and the United States have been closely following this program," he said.

Observers and analysts, comparing the U.S. stance against Iraq and North Korea (both dubbed as parts of a so-called "axis of evil" by Bush), noted the clear difference in handling both situations.

While North Korea admitted to having nuclear programs, the U.S. preferred to adopt a policy of "peaceful solution through consultation with allies and friends".