Saudi Arabia's crown prince asserted on March 15 that the kingdom will develop nuclear weapons if Iran does, in a television interview immediately denounced by Tehran.
Iran signed a nuclear deal with world powers in 2015 that prohibits it from developing nuclear weapons, and beyond that. Tehran has said it has no ambition to develop such weapons of mass destruction.
However, U.S. President Donald Trump has threatened to pull out of the nuclear deal, and Tehran has said that, if the United States withdraws, it will no longer be bound by the deal.
"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," Saudi Prince Muhammad bin Salman told CBS television in an excerpt from an interview released on March 15. The full interview is due to be aired on March 18.
Iranian Foreign Ministry spokesman Bahram Qasemi responded sharply, saying the Saudi prince was a "delusional naive person" who "never talks, but with lies and bitterness" and has "no idea of politics," Iranian television reported.
The Sunni Muslim kingdom, which has been making plans to develop a nuclear energy program that would enable it to acquire weapons-making capabilities, has clashed with Shi'ite-led Iran increasingly in recent years.
The two regional rivals stand on opposites in two regional civil wars in Syria and Yemen, and have also backed opposing sides in political clashes in Iraq and Lebanon.
Prince Muhammad serves as Saudi defense minister and, at 32, is heir to the Saudi throne. He is scheduled to meet this week with U.S. President Donald Trump, who regards the kingdom as a close U.S. ally.
Muhammad has previously clashed with Iran, saying in an interview last year that the kingdom would make sure any future conflict between the two countries "is waged in Iran."
His remarks prompted Iranian threats to hit back at most of Saudi Arabia except the holy cities of Mecca and Medina.
Saudi Arabia, in making plans to develop a civilian nuclear energy program, has refused to rule out acquiring technologies such as uranium-enrichment systems that could be used to develop nuclear weapons.
The United States, South Korea, Russia, France, and China have consortiums that are competing to build the country's first two nuclear reactors.
To get the Saudi's business, Trump reportedly has been considering departing from past U.S. policies of allowing U.S. nuclear corporations to sign deals only with countries that rule out acquiring technologies that have military applications.
Nuclear reactors use uranium that is enriched to around five percent purity, but the same technology can also be used to enrich the heavy metal to a higher, weapons-grade level.
Iran currently has uranium-enrichment capabilities, but they have been curbed under the nuclear deal, which requires it to restrict its nuclear activities in exchange for sanctions relief.