Peter MacKay said Sunday his focus is on his responsibilities as defence minister and not on getting the job as NATO's next secretary-general.
Speaking to reporters in Brussels, MacKay said his priorities include his work reforming the Canadian military, as well as the mission in Afghanistan.
"I have a tremendous amount of work to do with the Canadian Forces," MacKay said, adding he was "very focused on my country."
Canada has 2,500 troops stationed in volatile southern Afghanistan. Canada's military involvement in the country is scheduled to end in 2011.
MacKay's comments indicate that the current front-runner for the NATO job, Denmark's Prime Minister Anders Fogh Rasmussen, continues to gain support among the organization's 26 member states.
However, MacKay did call for an end to the tradition of choosing a NATO head exclusively from European countries, echoing previous comments made by U.S. Vice President Joe Biden.
NATO's top civilian job has been held by a European since the organization was created in 1949. The top military job is always held by a U.S. general.
The secretary-general serves as chairperson of meetings of NATO ministers and summits, while also overseeing day-to-day operations.
The job calls for the ability to build consensus among members on major security issues, which have increased in recent years.
For example, NATO troops are stationed in Afghanistan, which takes the organization well beyond its original scope.
Decisions must be made via a consensus among all members.
While Fogh Rasmussen is considered the front-runner to replace the Netherlands' Jaap de Hoop Scheffer, whose term ends at the end of July, both MacKay and Polish Foreign Minister Radek Sikorski are also in contention.
On Saturday, a senior U.S. official indicated that Fogh Rasmussen was the favourite, but indicated that Washington has not decided who to support.
There is no written agreement that sets a term limit on the position of secretary-general. However, an informal agreement among NATO countries sets a limit at five years.
With files from The Associated Press