Washington DC, Nov. 2 -- US President Donald Trump defended the American military action against Iran, saying Washington had acted to prevent Tehran from acquiring nuclear weapons, while describing the rise in oil prices amid the ongoing conflict as a "very small price to pay" for national and global security.

Speaking at a rally in Iowa on Sunday, ahead of the November 3 US midterm elections, Trump reiterated that preventing Iran from developing nuclear weapons was the reason behind the US military intervention.

"I stopped Iran from having a nuclear weapon," Trump said.

Explaining his decision to undertake military action, he said, "I said, 'let's make that journey into the Middle East because we cannot let Iran have a nuclear weapon....