Kremlin spokesman Dmitry Peskov said if President Trump chooses to pull out of the multi-nation agreement, consequences would be “inevitable.”
Trump is scheduled to announce his decision on the pact at 2 p.m. on Tuesday.
Earlier, Iranian President Hassan Rouhani has warned that the US will face a “historic regret” should it decide to withdraw from the nuclear agreement.
Since the accord between Iran and the six world powers was signed in Vienna in July 2015, the International Atomic Energy Agency (IAEA) has repeatedly confirmed Iran’s compliance with its commitments.
Washington will have to pay a heavy price for walking away from the deal, Iran’s Foreign Ministry Spokesman Bahram Qassemi said.