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 the Bill and Melinda Gates Foundation, which hosted Prime Minister Justin Trudeau, former President Barack Obama and Nobel Peace Prize winner Malala Yousafzai.

The event’s 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’s 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’re talking about governments like the Trump administration cutting foreign aid.

That’s right. The negative thing would be if the donor countries aren’t as generous, like they have been, if they are defunding for the new tools isn’t as generous. And if the recipient countries aren’t allocating the money and making sure the best delivery practices are being used. If you assume that we don’t do well on that, then in things like childhood death, we don’t 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’s 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’s 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 – is it not?

Yes. It was a disappointment that the president’s 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’re 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’s 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’re hoping to see some increases there.

It was an inspiring event today. But the guy who holds all the cards, Donald Trump, wasn’t there. Do you think his “America First” policy is at the expense of world development?

Well if you take it literally you’ve got to be very worried because it’s almost like saying there’s 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’t agree, I think it is a win-win deal. I’m worried that we’re questioning certain elements of international engagement that I think the U.S. should be proud of. But I don’t 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’t cut much, my optimism is not misguided there.