Russia said on Tuesday it had seen signs that the United States was making preparations at a site in Nevada to resume nuclear testing, but said Moscow would not restart its own testing programme unless Washington did.
Russian Deputy Foreign Minister Sergei Ryabkov made the comments as the State Duma, the lower house of parliament, urgently studies how best to revoke Moscow's own ratification of a landmark treaty banning nuclear tests.
"The indications are that there is or was, at least until recently, (preparatory) work underway at the Nevada Testing Site," the TASS state news agency cited Ryabkov as saying.
"If they go down this (testing) path, then the position that was stated by the president of the Russian Federation will be triggered, that we will be forced to mirror this as well. This is when a completely different situation arises, but the responsibility for whether it will or won't arise lies with Washington."
Russian lawmakers were given 10 days on Monday to study how best to revoke Moscow's ratification of the Comprehensive Nuclear Test Ban Treaty (CTBT), after President Vladimir Putin held out the possibility of resuming such testing.
Putin said last Thursday that Moscow could consider de-ratification to bring itself into line with the United States which has signed but not ratified the same treaty.
Putin's comments were widely seen by Western security experts as signalling that Russia, which has the world's largest nuclear arsenal, was holding out the possibility of resuming testing at a time when it is locked in a standoff with the West over Ukraine.
Ryabkov was cited as saying that Russia felt it had no choice but to align itself with Washington's nuclear testing stance and that the Russian foreign ministry was preparing draft legislation to de-ratify the treaty.
