OTTAWA - Canada's vote against a United Nations declaration of aboriginal rights was an "astonishing'' move for a country that claims to be a model of tolerance and diversity, says UN Human Rights Commissioner Louise Arbour.

"I have to register my profound disappointment,'' the former Supreme Court justice told a conference Monday organized by the Canadian Human Rights Commission.

She cited the aboriginal rights issue as one example of a deeper malaise, suggesting her native country is flagging in its historic commitment to rise above narrow self-interest on the world stage.

Arbour noted, for example, that Ottawa has also been slow to move on ratification of another UN convention on the rights of the disabled and has played a limited role in laying the organizational groundwork or a new UN Human Rights Council.

"Canada claims to be an important player in the international community on the advancement of human rights,'' she said.

"You cannot play if you're not on the rink. You cannot play the whole game sitting on the side, positioning yourself as the arbiter of others' performance without putting your own into question.''

Arbour shied away from any direct mention of Prime Minister Stephen Harper or his government, insisting her remarks were aimed at the public in general.

Speaking later to reporters, she reiterated her remarks about the Declaration on the Rights of Indigenous Peoples, which passed the General Assembly last month by a 143-4 vote. Canada joined the United States, New Zealand and Australia -- all countries with significant aboriginal populations -- in opposing the measure.

Arbour called it a "very surprising position for Canada to take after not only years (but) decades of progressive involvement on that issue . . . . I found it rather astonishing.''

The Conservative government has defended its position by saying the wording of the UN declaration was overly broad and conflicted with Canadian law and practice, especially on issues such as land claims and natural resources.

Justice Minister Rob Nicholson was in the audience for Arbour's speech Monday but brushed past journalists on his way from the room with no comment.

Arbour told the conference that many Canadians cling to an "unduly romantic vision'' of their country as an international peacemaker and honest broker on the world scene -- a vision largely rooted in the achievements of former Liberal prime minister Lester Pearson and the Nobel Peace Prize he won half a century ago.

It's true that Canada's international partners still see it as a country with a certain "moral weight'' because of its success in building a nation that respects individual liberties and cultural diversity, said Arbour.

But she cautioned that others also see Canada as a country that's increasingly driven by its national self-interest in global affairs.

"I think Canadians have an image of themselves that is now pretty dated, that is not reflective of the contemporary position.''