Iraq's Prime Minister says Iraqi forces are launching an operation to push Islamic State group fighters out of a patch of territory on the western edge of the country near the border with Syria.

Haider al-Abadi is announcing the push during a visit to the holy city of Karbala on Saturday during the Arbaeen pilgrimage that commemorates the martyrdom of Imam Hussein, the Prophet Muhammad's grandson and a central figure in Shiite Islam.

Iraqi forces retook Iraq's border crossing with Syria earlier this month in a U.S.-led coalition-backed operation that involved Iraqi army units, Iraqi special forces and local tribal fighters.

All that remains from the so-called "caliphate" that once stretched to the edges of Baghdad are patches of territory along the Euphrates in the deserts of Syria and Iraq.