Canadian Gen. Ray Henault, NATO's top soldier, said recent efforts to buttress the alliance's force in Afghanistan have made only limited progress, hampering efforts to improve security in the country.

"We have seen modest progress on force generation," said Henault, chairman of NATO's military committee, after talks with chiefs of staff from the 26 allied countries.

"There are still shortfalls, and we discussed the strategic risks and consequences associated with continued under-resourcing of the minimum military requirement," he said in a statement issued Wednesday.

Henault issued the comments after a series of meetings designed to drum up reinforcements for NATO's force of 41,000 in Afghanistan, which is facing the most violent year since the U.S.-led invasion to topple the Taliban in 2001.

Although the force has grown by 8,500 over the past year, NATO commanders on the ground say they need more helicopters, planes and mobile units to step up the fight against the Taliban.

"Given the deployed resources, we remain satisfied in the main with the pace and progress," Henault said. "With more, we could do more and do it faster."

Concern over casualties, costs and commitments elsewhere have made some allies reluctant to send more troops, particularly to the southern and eastern areas where most of the recent fighting has been centred.

Canada, the United States, and other countries such as Britain and the Netherlands have been pressing their allies to step up efforts during meetings of ministers and military brass in recent weeks.

NATO commanders are also seeking to persuade allies to send more teams of instructors to train the Afghan army so that it can eventually start to take over front-line security from the international force.

"Fielding more training and liaison teams for the Afghan National Army remains a key priority," Henault said, adding that such teams can produce "a large payoff for a relatively small investment."

Recent offers from NATO governments should take the number of embedded training teams to a number in the "low to mid-30s," compared with 26 last month, NATO spokesman James Appathurai said.

However, the alliance's target is 46 and growing, as more Afghan army units are put together.

Appathurai declined to say which countries had made new offers, but Germany and France have indicated they would both be sending more instructors.

Afghan units in eastern Afghanistan have recently taken the lead in some operations against the Taliban, with U.S. support. However, NATO commanders estimate it will take up to 10 years before the Afghans can stand alone.