US President Donald Trump on Friday warned Iran’s supreme leader Ayatollah Ali Khamenei, to be “very careful with his words.”

Taking to Twitter, Trump said, “The so-called ‘Supreme Leader’ of Iran, who has not been so Supreme lately, had some nasty things to say about the United States and Europe”.

Trump further tweeted, “Their economy is crashing, and their people are suffering. He should be very careful with his words!”

Trump remarks came after Khamenei’s blistering speech, in which he attacked the “vicious” United States and described Britain, France and Germany as “America’s lackey’s,” was a mistake.

Earlier, the United States has threatened to impose a 25 per cent tariff on imports of European cars if European Union governments continue to back the nuclear deal, according to German Defence Minister Annegret Kramp-Karrenbauer.

The 2015 agreement was struck in Vienna between Iran and France, Britain, Germany, the United States, China and Russia.

In response to that, Tehran has progressively reduced the number of its key commitments to an agreement that drastically limited its nuclear activities.

Earlier this week, Britain, France and Germany announced that they were starting the so-called dispute mechanism to try to bring Iran back into full compliance with its commitments under the accord.

During a sermon at Friday prayers in Tehran, Khamenei accused the “wicked” governments of Britain, France and Germany of “threatening Iran to take the nuclear issue to the (UN) Security Council.”

The supreme leader also accused the European governments of historic animosity towards Iran.

Earlier in the month, Trump had ordered the death of Qassem Soleimani, commander of the Quds Force of the Islamic Revolutionary Guard Corps considered a hero in the country, in order to “stop a war,” not start one.

Iran had termed the US action of “international terrorism” as “extremely dangerous and a foolish escalation”.

General Qasem Soleimani was among the eight people killed in a rocket attack by the US on Baghdad international airport.

Last week, Iran fired a volley of missiles at US troops stationed in Iraqi military bases, that left 11 American soldiers injured.

(With inputs from agency)