Article published on the 2009-06-15 Latest update 2009-06-15 12:54 TU
Mousavi sent a formal protest letter to the Guardians Council calling for it to annul the result of Friday's election.
"The Guardians Council has been advised to precisely examine the letter," state television quoted Khamenei as telling Mousavi during a meeting on Sunday.
A spokesperson for the council said it would meet on Tuesday with Mousavi to discuss the complaint.
"The final decision will be given within the statutory deadline," the spokesperson said.
Khamenei also told Mousavi to pursue his complaints over the election through legal means and settle the issue calmly, the television said.
EU foreign ministers on Monday called for a probe into the conduct of the presidential election.
In a statement the ministers, meeting in Luxembourg, also "expressed serious concern about the violence on the streets and the use of force against peaceful demonstrators."
In Tehran on Monday, thousands of Iranians defied a ban to join a mass opposition rally.
"Mousavi we support you! We will die but retrieve our votes!" the crowds shouted, as riot police stood guard.
Mousavi's website said that he would appeal for calm at the rally.