Russia has warned the United States against supplying Ukraine with Tomahawk cruise missiles.

Russian news agency TASS quoted Kremlin spokesman Dmitry Peskov on Monday saying, “In fact, dealing with such heavy missiles requires the involvement of American specialists in one way or another.”

Following Peskov’s remarks, a statement was issued by Deputy Chairman of the Security Council and former Russian President Dmitry Medvedev, who warned US President Donald Trump against such a move.

Medvedev wrote on Telegram that “delivering these missiles could end badly for everyone, especially for Trump himself.”

He added that when a Tomahawk missile approaches, it is impossible to know whether it is armed with a nuclear warhead or not. Russia, a nuclear power, has repeatedly threatened to use its nuclear weapons. Medvedev expressed hope that Trump’s threat remains empty.

Trump has not ruled out supplying Ukraine with Tomahawk cruise missiles. On board the presidential plane heading to the Middle East, Trump told reporters late Sunday that he wants to talk to Russia about this issue and ask if they want Tomahawk missiles flying towards them.

The range of Tomahawk cruise missiles reaches 2,500 kilometers and they can technically be equipped with nuclear warheads.