Russia has no biological weapons, the head of the Russian Defence Ministry's Chemical, Biological and Radiological Defence Troops, Lieutenant-General Viktor Kholstov, has said. He said Russia "has never developed, produced, accumulated or stored such weapons." The general said that because of recent developments in the world the Defence Ministry has tightened security measures to protect chemical and biological substances and major military facilities. The ministry wants an efficient mechanism to be worked out to verify observance of the 1972 international convention banning biological weapons, using objective criteria, Kholstov said. He expressed the ministry's "concern that the drawing up of a protocol to the convention can break down because of the United States' refusal to join in the work on the protocol."