Ayatollah Ali Khamenei
Ayatollah Ali KhameneiReuters

Iran’s Supreme Leader, Ayatollah Ali Khamenei, on Wednesday referred to US leaders as “idiots”, but also acknowledged that the sanctions imposed on his country by the United States were pressuring Iran.

"The sanctions do put pressure on the country and the people," Khamenei said in a speech in Tehran to commemorate an event from the 1979 revolution, according to Reuters.

"The Americans happily say that these sanctions are unprecedented in history. Yes, they're unprecedented. And the defeat that the Americans will face will be unprecedented, God willing," he added.

The Supreme Leader then lambasted US officials' approach to Iran as irrational describing them as “first-class idiots."

"Some US officials pretend that they are mad," Khamenei said. "Of course I don't agree with that, but they are first-class idiots."

US President Donald Trump withdrew in May from the 2015 nuclear deal between Iran and world powers. He later signed an executive order officially reinstating US sanctions against Iran. Two rounds of sanctions on the Islamic Republic have since gone into effect.

The move has resulted in increased tensions between the US and Iran. While Trump has indicated he is open for talks without preconditions with Iranian President Hassan Rouhani, the Iranian leader has dismissed Washington's call for new nuclear negotiations at the same time as it reimposes sanctions on his country.

Khamenei regularly attacks and threatens the US, and in October said Iran must deliver a slap and defeat America by defeating sanctions.

Last August, the Supreme Leader acknowledged he made a mistake in allowing the country's foreign minister to speak to his US counterpart during negotiations that led to the 2015 international nuclear agreement, admitting, “It was a loss for us.”