Thanks in part to the Bill & Melinda Gates Foundation's work, global childhood mortality rates have dropped by more than 55 percent since 1990, and 89 percent of the world's population is now vaccinated against common diseases. The proportion of people living in extreme poverty (defined as living on less than $1.90 a day) dropped to just nine percent in 2016, down from 35 percent in 1990.

But in a new report, the foundation warns that future progress is in jeopardy, writing "there is more doubt than usual about the world's commitment to development."

"In our own country, Congress is currently considering how to deal with the big cuts to foreign aid proposed in the president's budget. A similar mood of retrenchment has taken hold in other donor countries. Meanwhile, most developing countries need to do more to prioritize the welfare of their poorest citizens," Bill and Melinda Gates write

On "CBS This Morning" Friday, Bill Gates expanded on the warning.

"The 1 percent of U.S. budget that goes toward this is over five times what we [the foundation] spend, and so by partnering with the U.S. government and making sure it's money well spent, the potential is huge. But if that got cut back — for example, we showed [if] they cut the HIV spending by 10 percent, five million additional people would die between now and 2030," Gates, co-chair and trustee of the foundation, said.

In addition to global health, the former Microsoft CEO and co-founder spoke out on the Trump administration's recent decision to rescind the Deferred Action for Childhood Arrivals (DACA) program, saying he was "very proud" of Microsoft's response. Microsoft CEO Satya Nadella showed his support for "diversity and economic opportunity for everyone," including the "Dreamers" who work at the company. Microsoft president Brad Smith said changes in the program for undocumented young adults who grew up in the U.S. would "be a step backwards for our entire nation."

"It's great. We shouldn't let those 800,000 have that uncertainty or do anything against them. And that should be the top priority for any legislative agenda," Gates said.

Gates said bad immigration policy is "unjust and unwise economically."

"We benefited by having very talented people who want to come to the United States. Many countries are very envious that a lot of their top people see the freedom and the quality of the academics here, and so that's part of the reason why our universities and companies are so strong," Gates said. "So I think it would be a mistake from an economic point of view. Even worse though is how you treat people, including those already here."

As for his Microsoft legacy, Gates recently made headlines for expressing some regrets about the two-handed "ctrl-alt-delete" command on PCs. At a Bloomberg business forum this week, Gates said that if he could go back in time, he'd make stopping software a "single-key operation."

"It's a little tricky to tell people that these three strange keys do something special on your computer. Between us and IBM, that one wasn't as user-friendly as it should be. So we feel bad about that," Gates said on "CBS This Morning."

Watch the video above to see what Bill Gates thinks is "the next big frontier" of artificial intelligence.