Russia is not conducting nuclear tests but remains prepared to do so at any time, the defense minister said Wednesday during a trip to the country's main nuclear test site, Russian news agencies reported.

Sergei Ivanov said that the site on the Arctic archipelago of Novaya Zemlya is in a state of constant readiness to hold nuclear tests, but that Russia is now only conducting experiments that do not involve nuclear explosions, Interfax reported.

CountryWatch: Russia

"We proceed from existing reality and keep the test range in constant preparedness, while adhering to all our commitments," the agency quoted him as saying.

More than 100 countries have endorsed the Comprehensive Nuclear Test Ban Treaty, but to take effect it must be signed and ratified by 44 states that participated in a 1996 disarmament conference and possessed nuclear power or research reactors at the time. Only 34 have done so; the holdouts include China, India, Pakistan, Israel, North Korea and the United States, which has signed but not ratified the treaty.

Ivanov said that while Russia has ratified the treaty, "this does not mean we have stopped work in the nuclear sphere," RIA-Novosti quoted Ivanov as saying.

Ivanov, President Vladimir Putin and other officials have repeatedly stressed that Russia intends to maintain strong nuclear capabilities.

Ivanov last week announced plans to deploy new intercontinental ballistic missiles, saying that the nation needs a strong nuclear deterrent to protect itself from foreign "blackmail" — a comment referring at least in part to potential pressure from the United States.