Bill Gates will not deliver his keynote address at the India AI Impact Summit in Delhi, his philanthropic organisation said hours before the Microsoft co-founder was due to speak.

The Gates Foundation said the decision was made after "careful consideration" and "to ensure the focus remains on the [summit's] key priorities", but did not elaborate.

Gates's withdrawal comes amid a controversy over his ties to the late sex offender Jeffrey Epstein after he was named in new files released by the US Department of Justice in January.

Gates's spokesperson has called the claims in the files "absolutely absurd and completely false", and the billionaire has said he regretted spending time with Epstein.

Gates has not been accused of wrongdoing by any of Epstein's victims and the appearance of his name in the files does not imply criminal activity of any kind.

The Gates Foundation said Ankur Vora, president of its Africa and India offices, would speak at the summit instead of Gates.

The organisation added that it remained "fully committed" to its work in India to advance "shared health and development goals".

Gates's decision to not speak to the summit came after days of uncertainty over whether he would attend.

He is currently in India and had visited the southern state of Andhra Pradesh on Monday, where he reportedly discussed initiatives for boosting health, agriculture, education and technology.

After media reports speculated he would pull out of the summit, his foundation said on Tuesday he would deliver the address as scheduled.

Gates's withdrawal is a blow for the summit, which India has pitched as a flagship gathering to position the country as a global AI hub.

The five-day summit features policy discussions, start-up showcases and closed-door meetings on AI governance, infrastructure and innovation.

The event has also seen investment pledges by companies, including Microsoft, to expand AI access and infrastructure in countries such as India.

Delegates from more than 100 countries, including several world leaders, are attending the event.

But it has already been marked by some controversies over mismanagement on the first day and an Indian university's claims to have developed a robot dog - which turned out to be made in China.

Though Gates is not attending, other big names are appearing at the Summit.

OpenAI boss Altman said in a speech the world should "urgently" look to regulate AI.

"Democratisation of AI is the best way to ensure humanity flourishes," he said, adding that centralising the tech in one company or country "could lead to ruin".

"This is not to suggest that we won't need any regulation or safeguards," Altman added.

"We obviously do, urgently, like we have for other powerful technologies."

Indian Prime Minister Narendra Modi and French President Emmanuel Macron made similar calls for AI's democratisation and for a shared approach to innovation.

Addressing the Summit, Modi said there was a need to share technology "so that humans don't just become a data point for AI or remain a raw material for AI".

"AI must become a medium for inclusion and empowerment, particularly for the Global South," he said.

Macron, who earlier held bilateral talks with Modi, said there was a need to change the discussion around AI from "let's do more" to "let's do better together".

This theme was addressed by other speakers as well, including UN chief Antonio Guterres - who stressed the future of AI should not be "decided by a handful of countries" or left to the "whims of a few billionaires".

Google's chief executive Sundai Pichai underscored India's growing role in the AI landscape.

He said his firm was working on establishing an AI hub in the southern city of Vishakhapatnam, which he said would help bring jobs and cutting-edge AI to Indians.

Billionaire Mukesh Ambani meanwhile pledged to invest $110bn (£81.4bn) over the next seven years to build India's AI ecosystem, while Anthropic boss Amodei said it would like to work with India on "testing and evaluation of models for safety and security risks".