"Rawa's liberation operations began at dawn today," Iraq's Joint Operation Command (IJOC) said in a statement on Friday.
A spokesman for the command told CNN engineers had laid down a pontoon bridge across the Euphrates River to allow Iraqi forces to cross near the outskirts of the town.
Located in Anbar province in the Euphrates valley, Rawa is the last known Iraqi town still held by Daesh militants. Recapturing it would mean Daesh has been defeated in all of the country's towns and cities.
The push to liberate Rawa comes after Daesh was pushed from Qaim, its last major stronghold in Iraq, earlier this month.
The news of Qaim's liberation came the same day the Syrian military took back control of Deir ez-Zor, the terror group's last-held city in that country.