According to a 2004 South Korean assessment, North Korea also possesses a stockpile of chemical weapons estimated to amount to between 2,500–5,000 tons, including nerve, blister, blood, and vomiting agents, as well as the ability to cultivate and produce biological weapons including anthrax, smallpox, and cholera. As a result of its nuclear and missile tests, North Korea has been sanctioned under United Nations Security Council resolutions 1695 of July 2006, 1718 of October 2006, 1874 of June 2009, 2087 of January 2013, and 2397 in December 2017.