Saudi Arabia has warned that it will develop its own nuclear weapon if regional rival Iran acquires one.
Crown Prince Mohammed bin Salman told US network CBS News his country did not want to acquire nuclear weapons.
"But without a doubt, if Iran developed a nuclear bomb, we would follow suit as soon as possible," he added.
Iran limited its nuclear programme under a 2015 deal with several world powers - but US President Donald Trump has threatened to withdraw from it.
Saudi Arabia and Iran have long been rivals in the Middle East. Each is dominated by different branches of Islam - Sunni for Saudi Arabia, Shia for Iran - and they have historically supported opposing powers in regional conflicts.
In recent years, tensions have escalated over the wars in Syria and Yemen.
Prince Mohammed bin Salman, who is heir to the throne and also the Saudi defence minister, made the statement in an interview with CBS's 60 Minutes programme.
He also explained why, in November, he called Iran's supreme leader Ayatollah Ali Khamenei "the new Hitler of the Middle East".
"He wants to create his own project in the Middle East, very much like Hitler who wanted to expand at the time," the crown prince said.
"Many countries around the world and in Europe did not realise how dangerous Hitler was until what happened, happened. I don't want to see the same events happening in the Middle East."
Saudi Arabia, a key US ally, has been a signatory to the Treaty on the Non-Proliferation of Nuclear Weapons since 1988.
It is not known to have attempted to develop nuclear arms on its own but has reportedly invested in Pakistani nuclear weapons projects..
In 2013, Amos Yadlin, a former head of Israeli military intelligence, told a conference in Sweden that if Iran got the bomb, "the Saudis will not wait one month. They already paid for the bomb, they will go to Pakistan and bring what they need to bring."
Iran also signed the non-proliferation treaty, and has long insisted its nuclear programmes are for peaceful purposes only.
However in 2015, it signed onto an international agreement that saw crippling economic sanctions lifted in return for limitations on the programmes, which world powers feared Iran would use to create a nuclear weapon.
The deal restricted uranium enrichment, plutonium production, and allowed for increased inspections.
It was painted as a major victory by the administration of former US President Barack Obama. But his successor, Donald Trump, has called the deal "the worst ever".
Rex Tillerson, the former secretary of state, appeared to support the deal. But his new replacement Mike Pompeo has long shared the president's view that the agreement should be scrapped.
In January, Mr Trump extended sanctions relief on Iran for what he said would be the last time. The "waivers" suspending sanctions are to expire in May.
European leaders - including the UK, France, and Germany - have appealed to Mr Trump to preserve the agreement, which they say is working as intended.
Israel is widely considered to be the only nuclear-armed country in the Middle East but it refuses to confirm or deny it has a nuclear arsenal.