The United States believes North Korea may still consider the use of biological weapons as an option and the communist nation continues to develop its biological research and development capabilities, according to a State Department report.

The department made the assessment in this year's "Report on Adherence to and Compliance With Arms Control, Nonproliferation, and Disarmament Agreements and Commitments," which is also known as the "Compliance Report." The annual report was released last week.

In 1987, the North became a party to the Biological Weapons Convention that bans development, production, stockpiling and acquisition of microbial or other biological agents or toxins, as well as weapons and delivery means designed to use such agents or toxins.

But the only BWC-related declaration that the North has made was a confidence-building measure (CBM) declaration in 1990, the report said. CBM is the means by which parties to the convention disclose information annually.

"Available information indicates that North Korean entities engaged during the reporting period in a range of biological research and development activities," the report said. "The United States notes that North Korea may still consider the use of biological weapons as an option, contrary to the BWC."

The report did not elaborate on the "available information."

In the past, North Korea has rejected the view that it is not meeting its BWC obligations. It has also stated that it opposes the development and use of biological weapons, and that it does not possess a single biological weapon, the report said.

The report also said that the U.S. believes the North has followed through on its threat last year to "adjust and alter the uses of existing nuclear facilities" by restarting the 5-megawatt nuclear reactor and expanding the size of the uranium enrichment facility at its Yongbyon nuclear center.

"North Korea's activities violate U.N. Security Council Resolutions 1718, 1874, 2087 and 2094, and contravene North Korea's various international commitments under the 2005 Joint Statement of the Six-Party Talks," the report said.

The six-party talks have been stalled since the last session in late 2008. North Korea has said it wants an unconditional resumption of the talks, but Seoul and Washington have demanded Pyongyang first take concrete steps demonstrating its denuclearization commitment. (Yonhap)