In a post on his English-language Telegram channel, he wrote that Donald Trump is "the president of the United States, and the consequences of such words are inescapable: Russia will be forced to assess the expediency of conducting full-fledged nuclear tests itself."
Trump said he had instructed the Pentagon to resume nuclear weapons testing immediately, citing the fact that other countries are already doing so.
The US leader did not specify what kind of tests he was referring to or whether he meant nuclear warhead detonations.
During a meeting with the permanent members of the Security Council, Russian President Vladimir Putin emphasized that, while adhering to the Comprehensive Nuclear-Test-Ban Treaty, Moscow would respond if other participants, including the United States, violated the agreement.
He instructed the Defense Ministry, the Foreign Ministry, and the special services to study the feasibility of preparing for such tests. However, in an interview with TASS, Kremlin spokesman Dmitry Peskov emphasized that there is no talk of actual preparations at this stage.