"The Iraqi foreign ministry is sorry about the rash and unthinking decision taken by the US president," spokesman Ahmad Mahjoub said.

He warned of "dangerous developments" following Trump's announcement which could lead to "more of the destruction and wars that the region has already suffered".

Iraq has been a battlefield for the competing US and Iranian interests since the ousting of dictator Saddam Hussein in 2003.

The conflict-wracked country is gearing up for key parliament elections on Saturday amid a lull in violence five months since Baghdad claimed victory over the Islamic State group.

Iran exerts major influence over Iraq's political landscape -- particular its Shiite community -- while the US deployed troops to help battle IS.

Trump on Tuesday defied the wishes of major world powers by announcing the US would pull out of the historic nuclear accord and impose new sanctions on Tehran.

The agreement puts limits on Iran's nuclear programme in exchange of the lifting of international sanctions.