Humans should be worried about the threat posed by artificial intelligence (AI), Bill Gates has said.

The Microsoft founder said he didn't understand people who were not troubled by the possibility that AI could grow too strong for people to control.

Gates contradicted one of Microsoft Research's chiefs, Eric Horvitz, who has said he ‘fundamentally’ did not see AI as a threat.

Horvitz has said about a quarter of his team's resources are focused on AI.

During an ‘ask me anything’ question and answer session on Reddit, Gates wrote: "I am in the camp that is concerned about super intelligence. First the machines will do a lot of jobs for us and not be super intelligent. That should be positive if we manage it well.

His view was backed up by the likes of Musk and Professor Stephen Hawking, who have both warned about the possibility that AI could evolve to the point that it was beyond human control. Prof Hawking said he felt that machines with AI could ‘spell the end of the human race’.

Despite his own reservations, Gates wrote on Reddit that, had Microsoft not worked out, he would probably be a researcher on AI.

"When I started Microsoft I was worried I would miss the chance to do basic work in that field," he said.

He added that he believed the firm he founded would see ‘more progress... than ever’ over the next three decades.

"Even in the next 10 [years,] problems like vision and speech understanding and translation will be very good."

He predicted that, in that time, robots would perform tasks such as picking fruit or moving hospital patients.

But he admitted that he felt ‘pretty stupid’ because he cannot speak any language other than English.

"I took Latin and Greek in High School and got As and I guess it helps my vocabulary but I wish I knew French or Arabic or Chinese.

"I keep hoping to get time to study one of these - probably French because it is the easiest... Mark Zuckerberg amazingly learned Mandarin and did a Q&A with Chinese students - incredible," he wrote.