Donald Trump
Donald TrumpYonatan Sindel/Flash 90

US President Donald Trump vowed in an interview with Fox News on Sunday night not to let Iran get nuclear weapons, though he reiterated his reluctance to go to war.

"I will not let Iran have nuclear weapons," he told Fox News host Steve Hilton in an interview.

While Trump continued opposing military intervention, he indicated Iranian nuclear development would constitute an urgent exception.

"I don’t want to fight. But you do have situations like Iran, you can’t let them have nuclear weapons -- you just can’t let that happen," he said.

Trump recounted the costs of war which he said he wanted to avoid.

"With all of everything that’s going on, and I’m not one that believes -- you know, I’m not somebody that wants to go into war, because war hurts economies, war kills people most importantly -- by far most importantly," he said.

"I ended the Iran Nuclear Deal, and actually, I must tell you -- I had no idea it was going to be as strong as it was. It totally -- the country is devastated from the standpoint of the economy," Trump told Hilton.

The interview with Trump aired hours after he warned Iran on Twitter not to threaten his country.

“If Iran wants to fight, that will be the official end of Iran. Never threaten the United States again!” he wrote.

Tensions between the US and Iran have intensified in the past week, after the US military deployed an aircraft carrier and B-52 bombers to the Middle East. US officials said the move was made to counter “clear indications” of threats from Iran to American forces in the region.

Last week, Trump warned that Iran would “suffer greatly” if it targeted US interests.

“We’ll see what happens with Iran. If they do anything, it will be a very bad mistake. If they do anything they will suffer greatly,” he told reporters.

Previously, Trump urged Iran’s leaders to talk with him about giving up their nuclear program but also made clear he could not rule out a military confrontation with the Islamic Republic.

Iran rejected Trump’s overture, with Deputy Foreign Minister Abbas Araghchi saying, “The solution does not lie in the mediations or the phone call and the US has our phone numbers too.”

On Friday, a US official said the United States is "sitting by the phone" but has heard no message yet from Iran that it is willing to accept Trump's overtures for direct talks.