Trump warns Iran supreme leader to be 'careful with his words' following Friday sermon

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

"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 tweeted of Khamenei's comments earlier Friday in Tehran.

According to Trump, 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.

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

'Exploiting tragedy'

Iran's supreme leader said on Friday that demonstrations at home over the accidental downing of a Ukrainian airliner were unrepresentative of the Iranian people and accused the country's enemies of exploiting the disaster for propaganda purposes.

Leading the main weekly Muslim prayers in Tehran for the first time since 2012, Ayatollah Ali Khamenei said the January 8 incident was a "bitter" tragedy but should not be allowed to overshadow the "sacrifice" of one of Iran's most storied commanders, assassinated in a US drone strike.

His sermon came after a traumatic month for Iran in which it approached the brink of war with the United States and mistakenly shot down the Ukrainian jet, killing all 176 people on board.

"The plane crash was a bitter accident, it burned through our heart," Khamenei said in an address punctuated by cries of "Death to America" from the congregation.

"But some tried to... portray it in a way to forget the great martyrdom and sacrifice" of Major General Qasem Soleimani, the head of the foreign operations arm of Iran's elite Revolutionary Guards who was assassinated in Baghdad on January 3.

Khamenei said Iran's enemies had tried to use the plane tragedy to undermine the Islamic republic.

"Our enemies were as happy about the plane crash as we were sad," he said.

"The spokesmen of the vicious American government keep repeating that we stand with the people of Iran. You're lying," Khamenei said.

He also slammed Britain, France and Germany, which on Tuesday decided to trigger a dispute mechanism in the 2015 nuclear deal with Iran, following US threats to impose tariffs on European cars.

"It has been proven now, after about a year, that they are, in the true sense of the word, America's lackeys," he said.

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