The Baghdad talks will focus on ways to quell the violence in Iraq and will not address other issues, such as Tehran's disputed nuclear program. But they are seen as potentially significant amid high tensions between the two sides.
The talks will be led by the U.S. ambassador to Iraq, Ryan Crocker, and his Iranian counterpart, Hassan Kazemi-Qomi.
On May 26, Iran's foreign minister said the United States must change its policies in Iraq if the talks are to succeed.
Manuchehr Mottaki said the United States must admit its "wrong policies" for the talks to continue.
The two adversaries broke off diplomatic relations in 1980 after radical Iranian students stormed the U.S. Embassy in Tehran and held staffers hostage for 444 days.
(compiled from agency reports)