BRUSSELS, Belgium – NATO allies on Wednesday approved detailed plans to send up to 300 military instructors backed by hundreds of guards and support staff to Iraq in an expansion of the alliance’s military training program.

The approval sets up a meeting of officers from the 26 allies next week at NATO’s military headquarters in southern Belgium to muster troops for the mission, which would run a military academy outside Baghdad for Iraqi officers.

Alliance commanders want to have the expanded mission up and running before the end of the year.

However, the alliance’s top general added to concerns over the refusal of nations such as France and Germany to allow their troops to participate in the mission, even officers assigned to NATO headquarters.

“That is, of course, causing difficulties,” German Gen. Harald Kujat said. “We don’t have too many experts who can rotate.”

Kujat, chairman of NATO’s military committee, said he did not foresee difficulties in raising troops for the initial deployment of instructors and backup. But he said some nations’ refusal to allow their NATO officers to participate could cause longer term problems.

“It’s important that everybody contributes,” he said. “There is a certain obligation.”

NATO’s top operational commander, U.S. Gen. James Jones, has said 16 of the 26 allies have agreed to join the operation, which aims to train about 1,000 officers a year.

Opponents of the Iraq war such as France, Germany and Belgium have insisted they will not send troops to Iraq, although they have offered to help with training Iraqi forces outside the country.