Canada is sending troops back to Afghanistan to take part in an international security force, Defence Minister John McCallum announced in the House of Commons Wednesday.

The battle group and brigade-level headquarters will work to keep the peace in the Kabul area with the UN-mandated International Security Assistance Force (ISAF).

"Canada is willing to serve with a battle group and brigade headquarters for a period of one year starting late this summer," McCallum told the Commons. "We are currently in discussion with a number of potential partners."

CTV's Mike Duffy says 1,000 troops will leave for a six-month rotation that could be extended to up to a year. Other reports say between 1,500 and 2,000 troops could be sent. McCallum told reporters he could not yet give specifics on numbers, "but I can tell you it will be a sizeable contribution."

Canadian units who may be part of the deployment have not yet been identified.

The ISAF is assisting the Afghan interim administration, providing police security and stability in Kabul and in the rest of Afghanistan. The Germans assumed six-month command of the 4,000-strong force this week. Spain or Canada could take over once the German rotation is over.

The Alliance suggested the government is using the Afghanistan deployment as a cover for its unwillingness or inability to be on the front lines in Iraq. "This is a way out for them," said Alliance critic Leon Benoit.

McCallum says the decision is not related to any Canadian contribution to a conflict that may erupt in Iraq.

"We are not making any decision on the subject of Iraq. I'm talking to you today about Afghanistan," he responded to reporters. "Now, it is true that the more we send to one place, the fewer we may have available for other places."

Duffy says the deployment is not designed to free up American soldiers to go to Iraq, since the U.S. has not taken part in the ISAF mission.

Canada currently has two warships, two maritime patrol aircraft, three transport planes in the Gulf region searching for al Qaeda or Taliban operatives. In 2002, Canada deployed 800 soldiers to Afghanistan for six months as part of the war against terror.

On Wednesday, the Department of National Defence announced that 25 Canadian military planners were transferred to the U.S. command post in Qatar last week. McCallum says the forces are part of the ongoing work in Afghanistan -- not in Iraq.

"There is absolutely no commitment to Iraq at this time," McCallum said. "And should that ever happen, it will only occur with UN support following a deliberate decision with our government."