International aid to developing countries could take a major hit if U.S. President Donald Trump follows through with his proposal to cut funding -- an uncertainty that Microsoft founder and billionaire philanthropist Bill Gates is watching closely.

Gates was in New York City Wednesday for an event organized by which hosted Prime Minister Justin Trudeau, former President Barack Obama and Nobel Peace Prize winner Malala Yousafzai.

The event鈥檚 agenda: measuring the progress of global health and addressing pervasive gaps in treatment.

Earlier this year, Trump released his plan to drastically cut the Department of State and International Aid鈥檚 budget from $39.7 billion to $28.2 billion -- a decrease of 29 per cent. Meanwhile, he proposed to add $52 billion to the Department of Defense and $2.8 billion to the Department of Homeland Security.

In a sit-down interview with CTV National News Chief Anchor and Senior Editor Lisa LaFlamme, Gates discussed the importance of international aid.

LaFlamme: I wonder how you convince people that development is cheaper than war?

Gates: The UN is about crises. All organizations have to be able to do crises and to do the constant improvement at the same time. And so our Goalkeepers event, where we had a lot of government, UN people, a lot of young people, was to say, How are we doing on that report card for humanity?

Certainly the report does cite remarkable progress, but there is a red flag through it. And that is that progress is not inevitable. We鈥檙e talking about governments like the Trump administration cutting foreign aid.

That鈥檚 right. The negative thing would be if the donor countries aren鈥檛 as generous, like they have been, if they are defunding for the new tools isn鈥檛 as generous. And if the recipient countries aren鈥檛 allocating the money and making sure the best delivery practices are being used. If you assume that we don鈥檛 do well on that, then in things like childhood death, we don鈥檛 have any more improvement, or in HIV we actually go backwards and over 5 million additional people die because, in that case, we modelled a ten per cent funding cut.

Did you hear anything in the president鈥檚 UN speech that gave you any reassurances in terms of your own development goals?

Well, President Trump did mention the (President's Emergency Plan for AIDS Relief), Global Fund, President鈥檚 Malaria Initiative -- some of the amazing things. Actually, all three of those were started under President George W. Bush.

But PEPFAR is actually under Trump getting the biggest cut -- $1 billion cut 鈥 is it not?

Yes. It was a disappointment that the president鈥檚 recommendation on the budget was to cut the HIV money and many other things. And so it is scary that, will it be maintained or not, we鈥檙e not sure.

Canada is even down 4 per cent on its global aid contributions. Were you able to speak to Prime Minister Trudeau at all about that?

Absolutely. When it comes to Canadian aid, it鈥檚 spent very well, and so as he gets any sort of budget flexibility, the idea of development including gender-focused, child-focused, health-related things, we鈥檙e hoping to see some increases there.

It was an inspiring event today. But the guy who holds all the cards, Donald Trump, wasn鈥檛 there. Do you think his 鈥淎merica First鈥 policy is at the expense of world development?

Well if you take it literally you鈥檝e got to be very worried because it鈥檚 almost like saying there鈥檚 no win-win. That is, anything we spend on other people is like us being a sucker and not getting a good deal. So when he says that our 25 per cent is more than we should spend, I don鈥檛 agree, I think it is a win-win deal. I鈥檓 worried that we鈥檙e questioning certain elements of international engagement that I think the U.S. should be proud of. But I don鈥檛 think the jury is fully in on that.

I am an optimist in general, but I think specifically here the idea that in the end the U.S. won鈥檛 cut much, my optimism is not misguided there.