Miami, Florida - President Donald Trump on Friday reiterated his disappointment with NATO allies over their refusal to send military to help secure Iran's Strait of Hormuz and said Washington may not help them in the future if asked to do so.

"They just weren't there," he said at an investment forum in Miami.

"We spend hundreds of billions of dollars a year on NATO, hundreds, protecting them, and we would have always been there for them, but now, based on their actions, I guess we don't have to be, do we?" he added.

"Why would we be there for them if they're not there for us? They weren't there for us."

Since the start of the US-Israeli offensive against Iran a month ago, Trump has repeatedly voiced frustration over Western allies' lack of support and reluctance to commit forces to help reopen the Strait of Hormuz, a key sea lane for Gulf oil and gas exports vulnerable to Iranian attacks.

Traffic through the narrow waterway has ground to a virtual standstill, leading to a surge in global energy prices.

Six key powers – including Britain, France, Germany, and Japan – say they are ready to "contribute to appropriate efforts" but have not made any commitment.

Trump has reserved some of his toughest criticism for the North Atlantic Treaty Organization. Last week, he dubbed its other members "COWARDS," and declared the alliance was a "paper tiger" without the US.

On Thursday, he said on his Truth Social platform that the US "needs nothing from NATO."

"NATO nations have done absolutely nothing to help with the lunatic nation, now militarily decimated, of Iran."