Iraqi officials have expressed outrage at the United States' use of a small fleet of surveillance drones to help protect the US embassy, consulates and American personnel in Iraq, The New York Times reported.

The newspaper said the State Department began operating some drones in Iraq last year on a trial basis and stepped up their use after the last US troops left the country in December.

The US government plans to take bids for the management of drone operations in Iraq over the next five years, the report said.

The State Department drones carry no weapons and are meant to provide data and images of possible hazards, like public protests or roadblocks, to security forces on the ground, the paper noted. They are much smaller than armed drones.

But the US government needs formal approval from Iraq to use such aircraft there, the paper noted, citing unnamed Iraqi officials.

Such approval may be hard to get given the political tensions between the two countries, The Times said.

A senior American official said negotiations were under way to obtain authorization for the drone operations, but Ali al-Mosawi, a top adviser to Prime Minister Nuri Kamal al-Maliki; Iraq’s national security adviser, Falih al-Fayadh; and the acting minister of interior, Adnan al-Asadi, all said in interviews that they had not been consulted by the Americans, the report said.

"Our sky is our sky, not the USA’s sky," Asadi is quoted by the paper as saying.