Bill Gates has said there will be “almost no poor countries by 2035”, and that child mortality rates in the poorest nations will plummet to the same levels as in the US and UK in 1980.

The world’s richest man made the prediction in the Gates Foundation’s annual letter, in which he and his wife, Melinda, sought to dispel three common “myths” surrounding the issues of world poverty.

The foundation, which is expected to have given away the entire Gates fortune of around $67 billion (£40 billion) by the time the couple have been dead for 20 years, has published a letter for each of the last five years detailing global philanthropic progress.

Download the new Independent Premium app Sharing the full story, not just the headlines

Speaking to Forbes Magazine’s editor Randall Lane, Mr Gates said there will soon come a point where “you’ll have to give a reason why a country is poor”. He said that while it is difficult to make predictions for nations where politics hinders progress (naming North Korea as an example), for almost everyone else there are “good examples to learn from”.

Tackling the first myth, Mr Gates wrote: “Poor countries are not doomed to stay poor.

“I am optimistic enough about this that I am willing to make a prediction. By 2035, there will be almost no poor countries left in the world. Almost all countries will be what we now call lower-middle income or richer.

“It will be a remarkable achievement. When I was born, most countries in the world were poor. In the next two decades, desperately poor countries will become the exception rather than the rule. Billions of people will have been lifted out of extreme poverty. The idea that this will happen within my lifetime is simply amazing to me.”

Identifying a second myth, that foreign aid is a waste of money, Mr Gates said he was worried this was used as “an excuse for political leaders to try and cut back on it”.

“Broadly speaking, aid is a fantastic investment, and we should be doing more,” he wrote. “It saves and improves lives very effectively, laying the groundwork for long-term economic progress.”

Addressing a final myth, that saving the lives of children leads to overpopulation, Melinda Gates wrote that “this kind of thinking has gotten the world into a lot of trouble”.

Watch: the myths of poverty debunked

Daily coronavirus briefing No hype, just the advice and analysis you need Enter your email address Continue Continue Please enter an email address Email address is invalid Fill out this field Email address is invalid Email already exists. Log in to update your newsletter preferences Register with your social account or click here to log in I would like to receive morning headlines Monday - Friday plus breaking news alerts by email Update newsletter preferences

“Anxiety about the size of the world population has a dangerous tendency to override concern for the human beings who make up that population,” she said.

“When children survive in greater numbers, parents decide to have smaller families. Saving lives doesn’t lead to overpopulation - in fact, it’s quite the opposite.

“Creating societies where people enjoy basic health, relative prosperity, fundamental equality, and access to contraceptives is the only way to secure a sustainable world.”

In conclusion, the pair said: “We all have the chance to create a world where extreme poverty is the exception rather than the rule, and where all children have the same chance to thrive, no matter where they’re born. For those of us who believe in the value of every human life, there isn’t any more inspiring work under way in the world today.”

The Gates Foundation Annual Letter