U.S. President Donald Trump fired back Friday evening at Iran's Supreme Leader Ayatollah Ali Khamenei who earlier had mocked him as a "clown" – then in a subsequent tweet Trump said Iran's leaders "should abandon terror and Make Iran Great Again!"

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

Trump tweeted hours after Khamenei called him a "clown" in a rare public address.

In his first Friday prayers sermon for eight years, Khamenei threw his support behind the elite Revolutionary Guards after their belated admission that they had accidentally downed an airliner triggered days of street protests.

"The villainous U.S. government repeatedly says that they are standing by the Iranian people. They lie," Khamenei said in a tweet on Friday. "If you are standing with the Iranian people, it is only to stab them in the heart with their venomous daggers."

In another Twitter post on Friday evening, Trump sent out a message to Iranian citizens, including a riff on his 2016 campaign slogan, "Make America Great Again."

"The noble people of Iran - who love America - deserve a government that's more interested in helping them achieve their dreams than killing them for demanding respect," he said. "Instead of leading Iran toward ruin, its leaders should abandon terror and Make Iran Great Again!"

'They don't want war'

Pakistan's foreign minister, who has shuttled between Washington and Tehran in the course of a week, voiced confidence on Friday that Iran was seeking to lower tensions.

Foreign Minister Shah Mehmood Qureshi discussed Iran and Afghanistan's peace process on Friday with U.S. Secretary of State Mike Pompeo, five days after seeing Iranian President Hassan Rouhani.

While stopping short of saying that he was transmitting any message, Qureshi said he understood that the Iranians "did not want to escalate things." "They don't want war, they don't want further bloodshed," Qureshi told reporters in Washington.

The Iranians "highlighted the issues, the differences, they have had with other important countries in the region," he said, adding "They said they are willing to engage at any level and in any format."

(With input from agencies)