The British government may not meet its promise to slash troop levels in Iraq to 2,500 by the summer, defense officials indicated Tuesday.

A report, meanwhile, revealed that the cost for Britain of conflicts in Iraq and Afghanistan almost doubled in the last year to more than $6 billion.

In October, Prime Minister Gordon Brown promised to cut the number of British troops in Iraq to 2,500 — half the level at the time — starting in the spring. Officials said then that the cut would be completed by mid-2008.

On Tuesday, the Ministry of Defense said officials hoped to reduce troop numbers — currently about 4,100 — "over the coming months," but gave no figure and no timetable.

A spokesman said the size of the cut would be decided on the advice of military commanders and "entirely based on conditions on the ground."

"No decisions have been made regarding troop reductions or timing," he told The Associated Press on condition of anonymity in keeping with government policy.

Speaking in the House of Commons on Oct. 8, Brown said that, "subject to conditions on the ground, we plan, from next spring, to reduce force numbers in southern Iraq to a figure of 2,500."

The House of Commons Defense Committee said Monday that spending on campaigns in Iraq and Afghanistan for the current financial year would be just under $6.6 billion, a 94 percent increase on last year.

Costs have been rising despite a reduction in troop numbers in Iraq from 7,200 two years ago to about 4,100. The number of troops in Afghanistan has risen by about the same amount — from 5,000 in 2006 to 7,800 now.

The government attributed the increase to the need to purchase new equipment to protect troops against a changing insurgent threat.

"The threat changes, it constantly changes. The enemy learns and changes the threat to our people. We have to stay ahead of the game as best we can and it is not cheap," Armed Forces Minister Bob Ainsworth told the British Broadcasting Corp.

But opposition politicians said the figures revealed that the two military campaigns have been underfunded for years.

Last month, the Commons Defense Committee said the military was so overstretched by extended warfare in Iraq and Afghanistan that its performance and morale were deteriorating.

"We have been complaining for a long time that these operations are under-resourced," said Conservative defense spokesman Liam Fox. "It appears that this is something the government seems to belatedly recognize only now."

The decision of Brown's predecessor Tony Blair to commit British troops to the 2003 invasion of Iraq was deeply unpopular and overshadowed his final years in power.

British casualties in Iraq have declined since troops withdrew late last year from the southern city of Basra to an airport garrison on the city's edge where their focus is training Iraqi forces.

But British forces in Afghanistan, based in southern Helmand province, have seen heavy fighting with a resurgent Taliban.

A total of 175 British soldiers have died in Iraq since the March 2003 invasion, while 89 have died in Afghanistan.