Moscow: Russia's parliament took the first step on Tuesday towards revoking ratification of the Comprehensive Nuclear Test Ban Treaty, blaming what a top lawmaker called the irresponsible attitude of the United States to global security.
Parliament's lower house, the Duma, voted by 412 to zero, with no abstentions, to approve the withdrawal of the ratification in the first of three readings.
Russia says the aim is to restore parity with the United States, which has signed but never ratified the 1996 treaty, and that it will not resume testing unless Washington does.
But some arms control experts are concerned that Russia may be inching towards a test that would be perceived as a threatening signal by the West at a time of heightened confrontation over Russia's war in Ukraine.
No country except North Korea has conducted a test involving a nuclear explosion this century. At least one senior Russian security expert has said Russia should test a nuclear bomb as a warning to the West, but President Vladimir Putin said on Oct.5 he was not ready to say whether a test was needed or not.
Swift and near-unanimous passage of the deratification bill was guaranteed after 440 of the Duma's 450 members attached their signatures to it as sponsors last week.
"In the interests of ensuring the security of our country, we are withdrawing the ratification of the Comprehensive Nuclear Test Ban Treaty," Duma Speaker Vyacheslav Volodin said before the start of Tuesday's session.
Volodin said that while Russia had ratified the 1996 treaty in 2000, Washington had failed to ratify because of its "irresponsible attitude to global security issues".
"The Russian Federation will do everything to protect its citizens and to maintain global strategic parity," Volodin said.
While Russia is revoking ratification, it will remain a signatory to the CTBT and says it will continue to supply data to the global monitoring system which alerts the world to any nuclear test.