Iran condemned on Tuesday a US move to deploy low-yield nuclear missiles on submarines, saying at a disarmament conference that this has made nuclear war "more likely".
Earlier this month, the US Defense Department Navy had fielded a low-yield, submarine-launched ballistic missile warhead, which the Pentagon says is needed to deter adversaries like Russia.
For its part, Moscow has already expressed alarm at the decision.
Low-yield nuclear weapons, while still devastating, have a strength of less than 20 kilotons, which is about the same as the atomic bomb dropped on Hiroshima, Reuters reported.
"Such provocative actions must be condemned," Mohsen Baharvand, Iran's deputy foreign minister for international and legal affairs, told the Conference on Disarmament in the UN building in Geneva.
"A new nuclear arms race is being accelerated," he stressed.
Washington accuses Iran of seeking to develop nuclear arms, an accusation Tehran denies.
Iran says the goal of nuclear programme is to generate energy. The nuclear dispute is at the heart of tensions between the two countries.
