Nato is running short of precision bombs and other munitions in its Libyan operation against the forces of Libyan leader Muammar Gaddafi, The Washington Post reported late on Friday.
Citing unnamed senior Nato and US officials, the newspaper said the shortage highlights the limitations of Britain, France and other European countries in sustaining even a relatively small military action.
The scope of the problem was not mentioned.
The shortage of European munitions, along with the limited number of aircraft available, has raised doubts among some officials about whether the United States can continue to avoid returning to the air campaign, the report said.
So far, the Nato commander has not requested their deployment, The Post noted.
But several US military officials said they anticipated being called back into the fight, the paper said.
Washington pulled back around 50 combat planes from Libyan operations last week after handing over control of the mission to Nato, although since then they took part in some missions to take out Kadhafi's air defense systems.
Currently, only six out of 28 nations are conducting air strikes, while France and Britain carry out half of them. The other half are conducted by Belgium, Denmark, Norway and Canada.
A senior administration official said he expected other countries to announce "in the next few days" that they would contribute aircraft equipped with the laser-guided munitions, The Post pointed out.