Iranian Foreign Minister Hossein Amir-Abdollahian left for Iraq on Friday to participate in a regional summit convened by the government of Prime Minister Mustafa Al Kadhimi.
The foreign ministry said Mr Amir-Abdollahian had left to attend a "meeting to support Iraq".
Iranian President Ebrahim Raisi, who took office this month, was also invited to the Baghdad summit but it is not clear if he will attend.
The meeting on Saturday seeks to give Iraq a "unifying role" to tackle the crises shaking the region, according to sources close to the Iraqi prime minister.
Egyptian President Abdel Fattah El Sisi, Jordan's King Abdullah II and French President Emmanuel Macron will attend, but the participation of leaders from other countries invited to the summit, including Saudi Arabia and Turkey, has not been confirmed.
Iraq is seeking to establish itself as a mediator between Arab countries and Iran.
Baghdad has since April been brokering talks between Saudi Arabia and Iran on mending ties severed in 2016.
Mr Raisi has said he sees "no obstacles" to restoring ties with Riyadh.