President Hassan Rouhani declared the end of the so-called Islamic State militant group Tuesday.
Rouhani said he wished to thank all the "warriors of Islam" for helping to "put an end to a group that did not bring anything for us but evil, misery, destruction, murder and savagery."
"The bulk of the work was done by the people and armies of Syria, Iraq and Lebanon and we helped them out of our religious and Islamic duty," he said at the Fifth National Congress of the House of Farmers in Tehran, according to a statement published on the president's website.
On Sunday, the Syrian army and its allies assumed complete control over Albu Kamal, Islamic State's last significant town in Syria, Reuters reported. Islamic State's area of rule has diminished throughout the year as a result of two rival military campaigns.
An Iraqi soldier holds an Islamic State flag during a battle with Islamic State militants, north of Mosul, Iraq.
However, Western intelligence agencies have warned that the militant group may still be able to inspire attacks on civilians around the world.
Rouhani said he would meet with Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan on Wednesday to discuss the future of Syria and the region.