U.S. Vice-President Joe Biden on Tuesday said candidates from all NATO countries will be considered for the military alliance's top job -- refusing to confirm whether Defence Minister Peter MacKay is a frontrunner for the job.

On Sunday the Washington Post reported that MacKay had the support of the Obama administration, but neither Biden nor MacKay have confirmed that.

Biden is in Brussels to consult with European allies and explore options for the North Atlantic Treaty Organization to move forward in Afghanistan. The Post reported he would also be lobbying for MacKay's selection for the job.

But during a press conference with NATO's current Secretary-General Jaap De Hoop Scheffer on Tuesday, Biden refused to confirm U.S. support for MacKay.

He said all NATO countries should be encouraged to provide candidates to replace Scheffer, a Dutchman.

MacKay has certainly hinted that he is open to the role. On Monday he refused to rule himself out and said all nationalities should be considered. The job has traditionally gone to a European.

"I don't think that traditions, in the sense that geography should be a restriction on any position in NATO," he said on Monday.

"I don't believe that a person's nationality, given the number of NATO countries there, should ever be a bar to ascendency of any role in NATO."

MacKay also mentioned Canada's history as a 60-year member of NATO, and key roles Canada has played in the organization.

According to some reports, Danish Prime Minister Anders Fogh Rasmussen has the support of the U.K., France and Germany for the job.

Rasmussen has so far refused to confirm or deny the report.

NATO has had 11 secretaries general since 1952, when the post was created. All have been western Europeans.

NATO's top military post has traditionally gone to an American. That is currently the case, with Gen. John Craddock currently holding the position.

The four-year appointment is made by concensus among the 26 member nations.

Scheffer's replacement will be chosen during a two-day summit in early April, which will be co-hosted by France and Germany.

Their main objective will likely be to bring about a successful end to the war in Afghanistan.

Biden on Tuesday urged NATO members to join in the fight against extremist groups in the country, saying instability there is a threat to all NATO member countries.

Biden asked for ideas to help win the war, part of U.S. President Barack Obama's strategy to bring more European partners into the fight.

The U.S. is sending 17,000 more U.S. troops to Afghanistan in the next year, to add to the 38,000 currently there.