GENEVA—Russian Deputy Foreign Minister Sergei Ryabkov said on Thursday Russia would not be the first to test a nuclear device, following Moscow’s suspension of the New START nuclear arms control treaty with the United States.

Addressing reporters at the Russian mission in Geneva after a disarmament conference, Ryabkov said Moscow would not carry out tests if Washington also refrained, but that Russia still had to prepare for the worst.

Ryabkov also accused the United States of providing intelligence on the location of strategic sites inside Russia to Ukraine, for it to attack them with drones.

In December, Russia’s Engels air base near the city of Saratov, home to part of its nuclear-capable strategic bomber fleet and at least 600 kilometers (370 miles) from Ukrainian territory, was hit by drone attacks. Ukraine did not claim responsibility for the attacks, but celebrated them.