US President Barack Obama plans to withdraw his 40,000 troops from Iraq by the end of the year after negotiations on keeping some forces there failed, a move some US politicians say could give Tehran more room to assert its influence.
"The uniform stance of all tribes and religions in Iraq over America's pressure to get legal immunity for its occupying servicemen, and ultimately the coercion of America to exit Iraq, constitute a golden page in that country's history," Supreme Leader Ayatollah Ali Khamenei said after a meeting with Iraqi Kurdistan President Masoud Barzani, the ISNA news agency reported.
The troops are leaving more than eight years after a US-led invasion toppled Iraqi President Saddam Hussein in 2003.
Tehran welcomed the fall of Saddam, a secular Sunni Muslim who took majority Shiite Iraq into a bloody 1980-88 war with Iran, but has always criticized US military intervention.
While it has been rebuilding ties with post-Saddam Iraq, Iran's relations with the United States have worsened. Washington has warned Tehran not to underestimate its large military presence in other nearby countries.
The two nations broke ties after radical students seized the US embassy in Tehran following the 1979 Islamic revolution.
Secretary of State Hillary Clinton's announcement on Wednesday of plans for a "virtual embassy" to reach out to Iranians was received in Tehran with derision.
"If America wants to open a virtual embassy in Iran, the young officers of soft war will occupy that as well," Mohammad Reza Kashefi, a member of the Basij student militia, told the semi-official Fars news agency.
"Ms Clinton has confused diplomacy with a toy," said parliament speaker Ali Larijani.
Clinton said the "virtual embassy" website would be open by the end of the year and it would provide Iranians with information on visas and other programs.
On Saturday, Foreign Minister Ali Akbar Salehi said Iran wanted ties with all countries except Israel, but that US policy made any rapprochement with Washington impossible.
Obama has not ruled out military action if needed to stop Iran getting nuclear weapons, which Tehran denies seeking.
Washington is pressing for new sanctions on Iran after uncovering what it says was an Iranian plot to assassinate the Saudi ambassador in Washington.
