TORONTO -- The secretary general of the United Nations is calling on Canada to boost its overall foreign aid budget to meet an ambitious international target.

Ban Ki-moon urged Canada and all G7 countries to commit 0.7 per cent of GDP on overseas development, significantly more than the 0.3 per cent Canada currently spends.

Ban's comment injected a dose of unexpected public criticism of the Harper government's sometimes controversial development agenda, which has included a freeze on aid to bring down the deficit.

Ban called for the increased spending Friday while standing alongside Prime Minister Stephen Harper at a news conference wrapping up the PM's three-day international child and maternal health summit in Toronto.

Ban's comment on the 0.7 target represented a gentle dose of public criticism of the prime minister who has lately basked in the adulation of several high-profile international figures, especially after Thursday's commitment of $3.5 billion in additional spending on child and maternal health over the next five years.

Helping newborns and mothers in the developing world has become Harper's signature foreign development priority. In Ban, Harper won wholehearted public support from the chief of the UN, an organization he has often criticized and been accused of snubbing.

Ban said the commitment will create momentum in the effort to save some of the 2.9 million babies who die in the first month of life -- one million of them on the day they are born.

"I call on other leaders of the world and business leaders of the world to follow Canada's example," he told the summit to applause.

But afterwards Ban chided Harper on the need to do more to boost broader development spending when asked about the issue at the news conference.

Ban said he is grateful for that contribution and for Canada's continuing support in humanitarian crises such as the civil war in Syria.

But he said he nonetheless believes it is within Canada's grasp to match the spending threshold.

"This overall agreed target should be met," Ban said. "I sincerely hope that the countries of the OECD and particularly G7 should lead by example.

Canada targets its foreign aid spending at programs that produce results, Harper said.

"It's the philosophy of our government and, I believe, of Canadians more broadly that we do not measure things in terms of the amount of money we spend, but in terms of the results we achieve."

Ban and Tanzanian President Jakaya Kikwete heaped praise on Harper as the trio wrapped up the summit, a centrepiece of the prime minister's long-standing efforts to tackle the issue of mother-child health around the world.

"I go back home totally satisfied that I've been to a very successful summit, a very useful summit," Kikwete said.

He said he is "excited that from now on there is going to be acceleration and beyond 2015 we're going to see more robust interventions to finish the unfinished business."

The two men thanked Harper for his commitment to maternal and child health and his promise to galvanize the world community to further support the cause.

Harper himself will do just that next week when he meets his fellow G7 leaders in Brussels, where he is expected to push for further global support of his efforts to improve maternal, newborn and child health.

Much remains to be done, because even one child's death from a preventable cause is one too many, but progress has indeed been made, Harper said.

But he indicated he's sensitive to the fact that some of his G7 partners are in worse economic shape than Canada.

NDP development critic Helene Laverdiere said she is concerned about $370 million worth of cuts to Canada's overall international aid spending.

While countries like Britain are hitting the 0.7 per cent target, Canada's official development assistance is at an almost record low, she said.

"We want Canada to commit to raising our ODA to 0.7 per cent."

Anthony Lake, the chief of the United Nations Children's Fund, said child welfare issues should transcend partisan politics.

"I do not know his (Harper's) motives. I'm sure parts of them are of genuine passion for children," Lake told The Canadian Press.

"And a part of it is probably political. And that's a good thing. We are all trying to make these issues part of the political scene because there should be a popular demand for dealing with the welfare of children around the world."

Overall, Harper's efforts won broad support from the many international leaders who participated in the Toronto summit.

"In a world of great knowledge and wealth, no child should die from preventable illness, and no mother should lose her life while giving birth -- yet too many women and girls are being left behind," Ban said.

In a poignant moment during his speech, Ban explained why as travels the world advocating for women and children, it is "an issue close to my heart."

Ban told a story that he's never mentioned in public before: he had an older sister and brother who died soon after birth.

Ban said food was scarce in his South Korean village and women dreaded giving birth.

"I should have been the third child," Ban said.

"I had an elder sister and elder brother, according to my mother. But unfortunately they died soon after their birth. I have no memory (of them) at all."