RIYADH — Saudi Arabia will develop nuclear weapons if its arch-rival Iran does so, the kingdom’s crown prince said in remarks released on Thursday, raising the prospect of a nuclear arms race in a region already riven with conflict.

“Saudi Arabia does not want to acquire any nuclear bomb, but without a doubt if Iran developed a nuclear bomb, we will follow suit as soon as possible,” Prince Mohammed bin Salman told CBS in an interview that will air in full on Sunday.

The Saudi kingdom has been at loggerheads with Iran for decades. The countries have fought a long-running proxy war in the Middle East and beyond, backing rival sides in armed conflicts and political crises including in Iraq, Syria, Lebanon and Yemen.

He downplayed Iran’s power during the interview, saying that Iran was far from being a rival to Saudi Arabia.

Iran’s Foreign Ministry spokesman Bahram Qasemi reacted harshly, saying the Saudi crown prince was a “delusional naive person” who has no idea of politics, Iranian state TV reported on Thursday.

“He has no idea of politics apart from bitter talk that emanates from a lack of foresight … His remarks do not deserve a response, because he is a delusional, naive person, who never talks, but with lies and bitterness,” Qasemi said.

Prince Mohammed, who also serves as Saudi defense minister, said last year that the kingdom would make sure any future struggle between the two countries “is waged in Iran”, prompting Iranian threats to hit back at most of Saudi Arabia except the holy cities of Mecca and Medina.

Riyadh has criticized the 2015 deal between world powers and Tehran under which economic sanctions on Iran were lifted in return for the Islamic Republic curbing its nuclear energy program. U.S. sanctions will resume unless President Trump issues fresh “waivers” to suspend them on May 12.

The comments by Prince Mohammed, who at 32 is heir to the throne, also have implications for Israel, another U.S. ally which neither confirms nor denies the widespread assumption that it controls the Middle East’s only nuclear arsenal.

Israel has long argued that, should Iran develop nuclear weapons, it would trigger similar projects among the Persian power’s Arab rivals and further destabilize the region.

It has never joined the 1970 nuclear Non-Proliferation Treaty (NPT) and has said it would consider inspections and controls under the NPT only if was at peace with its Arab neighbors and Iran.