The United Nations' humanitarian chief says Canada is making a difference on the ground in Afghanistan and should stick with its commitment to the war-torn country.

Sir John Holmes was in Canada to meet with Foreign Affairs Minister Maxime Bernier and Intergovernmental International Cooperation Minister Bev Oda to discuss Canada's role in international relief efforts.

He told CTV's Canada AM that the nation is setting an example on the international stage, and shouldn't abandon its efforts in Afghanistan.

"Canada is playing a very important role both on the security side but also on the development and reconstruction and humanitarian side," Holmes said.

"So I think it's very important that Canada is there for the long run. I think it's very important the international community sticks with Afghanistan for the long run. We've seen in the past what happens if you're in there for a short time and then pull out. The problems just reoccur."

Holmes, a Briton, was appointed earlier this year as the UN's undersecretary-general for humanitarian affairs and emergency relief coordinator by United Nations Secretary General Ban Ki-moon.

On Afghanistan, he acknowledged that there are major struggles and said the progress isn't always obvious. But he maintained that little by little, the situation is getting better.

"There are some difficulties there in the short term," Holmes said.

"There are big security problems. There are some humanitarian problems here and there. But I think overall, if you look back at the situation over the last five or six years, we've come a long way and need to stick with it."

Earlier this week, the Conservative government's speech from the throne suggested Canada should extend its commitment in Afghanistan until at least 2011, but was vague about the military's role during that period.

Prime Minister Stephen Harper said earlier this year that Canada's combat role would end by 2009 unless there was a parliamentary vote to extend the mission.

Holmes wouldn't say how long he believes Canada should remain in Afghanistan.

"I can't put a time scale on that and it wouldn't be for me to do so anyway. But I think it's important to hang in there and to be taking the progress that we've been making for granted."

Holmes also said Canada could help play a role in bringing stability to the troubled Darfur region of Sudan. He pointed out that a number of Canadian non-governmental organizations are already helping bring relief to those affected by the conflict -- work he described as "difficult and dangerous but worthwhile business."

"What we want to see is that people that have been displaced are finally able to go home. Again, that needs a continuing concerted effort from the international community and Canada is a very important part of that," Holmes said.

"Canada is a very important player in general in the humanitarian effort, in the international effort in situations like this and that's the reason I'm here, to try and strengthen that partnership between the UN and Canada and try and strengthen the role that Canada can play."

Holmes said he hopes to use his new position to co-ordinate, enhance and improve humanitarian global relief efforts, both in conflict zones such as Darfur, and after natural disasters such as the tsunami.

Natural disasters appear to be more and more frequent, he said.

"The effects of climate change are already very visible in the amount of floods and other extreme weather events we've seen this year," Holmes said.

"And I feel this is a trend we're going to have going forward. So there's an enormous challenge there. There are people suffering right now in all sorts of countries. We can do things to help them. We can be effective. I think the UN can be very effective as a driver and co-ordinator of that."

He said the effects of that type of front-line work are visible and immediate.

"Either you save lives and help people with a semblance of dignity, or you don't. So you see immediately whether you're achieving something."