Iran's Supreme Leader Ali Khamenei, during a meeting with his Iraqi colleague, called on Baghdad to ensure that US troops leave "as soon as possible", according to his official website.
"You must make sure that the Americans withdraw their troops from Iraq as soon as possible because expelling them has become difficult whenever they have had a long military presence in a country", Khamenei was quoted as saying.
The statement comes amid reports about the White House's plans to designate Iran's Revolutionary Guard Corps (IRGC, part of the Iranian armed forces) a foreign terrorist organisation (FTO) on 8 April.
On 26 March, the United States introduced a new round of sanctions against Iran by adding 16 entities and nine individuals to the sanctions list over their alleged financial support of the IRGC and other units of the Iranian Armed Forces.
Tensions between the United States and Iran have escalated since Washington withdrew from the Iran nuclear agreement last year and reinstated sanctions against Tehran. The nuclear agreement envisaged the gradual lifting of sanctions in return for Iran keeping its nuclear programme peaceful.