The Obama administration is flying armed aircraft over Iraq, defense officials said on Friday, adding that the flights were aimed at gathering intelligence.

The Obama administration is flying armed aircraft over Iraq, defense officials said on Friday, adding that the flights were aimed at gathering intelligence and ensuring the safety of U.S. personnel on the ground rather than conducting strikes.

"What I would tell you is that we continue to fly both manned and unmanned aircraft over Iraq at the ... Iraqi government's request, predominantly for reconnaissance purposes. Some of those aircraft are armed," Rear Admiral John Kirby, a Pentagon spokesman, told reporters.

"The reason that some of those aircraft are armed is primarily for force protection reasons now that we have introduced into the country some military advisers whose objective will be to operate outside the confines of the embassy," he said.

The United States has increased manned and unmanned reconnaissance flights over Iraq - to about 30 to 35 a day - in an effort to help Prime Minister Nuri al-Maliki's government repel the advance of terrorists from the so-called 'Islamic State in Iraq and the Levant' (ISIL).

More than two years after U.S. forces withdrew, the White House has ruled out sending troops back into combat in Iraq, but it has dispatched military advisors and said it would consider air strikes against the gunmen groups, who have seized cities and towns across western and northern Iraq.

U.S. intelligence about the ISIL advance is improving but it could take weeks to complete a detailed picture of the threat, and any possible strikes do not appear imminent, U.S. officials said.

The Obama administration also has been working to speed up delivery of U.S. weaponry that Iraq is buying from the United States.

Iraq has requested 800 Hellfire air-to-ground missiles, which enable helicopters to battle tanks and other armored vehicles, in addition to the hundreds of Hellfire missiles that should be delivered to the country in coming weeks, Kirby said.

"We're processing that as we speak," he said.