Prime Minister Stephen Harper is defending the Canadian ambassador to Afghanistan, who has reportedly offered to resign over fears leaked diplomatic cables will damage relations with Kabul.

A report in Thursday's Globe and Mail indicates that William Crosbie, Canada's ambassador to Afghanistan, has written to Ottawa to say he is concerned about what may come out on the WikiLeaks website.

The newspaper reports that Crosbie has seen a copy of a memo that will appear on WikiLeaks that quotes him criticizing Afghan President Hamid Karzai.

When asked about the criticisms, Harper replied "Crosbie doesn't represent the government of Afghanistan, he represents the government of Canada in Afghanistan."

Harper added it's well known that Canada has been "outspoken in its concerns about some aspects of governance in Afghanistan."

Foreign Minister Lawrence Cannon said it's the role of ambassadors to criticize and raise concerns.

"Our government raises concerns regarding issues of democracy, human rights and rule of law directly with the Afghan authorities, and we expect our ambassadors to do exactly that," Cannon said in the House of Commons Thursday.

NDP Leader Jack Layton asked during question period why Canada should continue training Afghan soldiers until 2014, if Ottawa thinks the Afghan government is so corrupt.

"The government of Canada will continue to make its concerns known to the government of Afghanistan . . . our ultimate goal is to leave Afghanistan to the Afghans and to create a more secure, and safe country," Cannon replied.

Former diplomat Colin Robertson said it is the right move for Crosbie to step down if the memo will be as damaging as he predicts.

"He's the senior diplomat who presumably has had the respect of President Karzai and when he's alerting the Canadian government, he's saying: ‘Look, this relationship could be in jeopardy, so we'll have to take stock over the coming days depending on what comes out,'" Robertson told CTV's Canada AM from Ottawa on Thursday morning.

In Afghanistan, there was no official reaction to the reported content of the memo from the Canadian or Afghan governments, or from Ahmed Wali Karzai the powerful brother of the Afghan president who may also be named in the memo.

CTV's Ben O'Hara-Byrne said it appears that "everyone is just waiting to see what exactly was said" in the memo that has still not been published online.

Since Sunday, the controversial WikiLeaks website has been posting confidential U.S. diplomatic cables on the Internet. A few hundred have been published so far, with the website planning to publish more than 250,000 over time.

The cables, which were not meant for public consumption, have ignited daily diplomatic fires that the U.S. has been forced to snuff out as the candid observations of its embassy staff have been made public.

In the case of Canada, one diplomatic cable suggested the country has an "inferiority complex" when it compares itself to the United States.

Canadian officials have said the WikiLeaks revelations will not impact the relationship between the two countries and U.S. Ambassador David Jacobson echoed that sentiment, saying Washington appreciates the strong support it has received from Ottawa.

"Canada is a real friend to the United States," Jacobson told CTV's Canada AM during an interview from Ottawa on Thursday morning.

"We truly appreciate the sentiments of the foreign minister and others in the government who have made it clear that this isn't going impact on what is a fundamentally strong relationship."

With files from The Canadian Press