Iraq PM made the speech in north Iraq, footage of which was posted online.
Iraqi Prime Minister Haider al-Abadi said Wednesday that he will not hesitate to strike "terrorist sites" in neighbouring countries, after Baghdad carried out air raids in Syria last month.
"I will not hesitate to strike terrorist sites in neighbouring countries, if they threaten the security of Iraq," Abadi said in a speech in north Iraq, footage of which was posted online.
Iraqi forces are fighting to retake Mosul from the Islamic State group, but the jihadists also hold significant territory in neighbouring Syria.
Abadi announced Iraqi strikes against IS near the border in Syria that were believed to be the first of their kind by Baghdad's forces.
Emerging from the chaos of the civil war in neighbouring Syria, IS seized control of large parts of Syria and Iraq in mid-2014, declaring its Islamic "caliphate" and committing widespread atrocities.
Iraqi forces backed by US-led air strikes and other support have since regained much of the territory they lost to the jihadists.