The United States has pledged to triple nuclear energy generation around the world by 2050 to cap an increase in global temperatures at 1.5 degrees Celsius.

The declaration was announced at the 28th annual UN Conference of the Parties, or COP28, in the United Arab Emirates, on Saturday with US climate envoy John Kerry, French President Emmanuel Macron and other leaders attending.

The declaration recognizes "the key role of nuclear energy in achieving global net-zero greenhouse gas emissions."

It says the participants in this pledge will "commit to work together to advance a global aspirational goal of tripling nuclear energy capacity from 2020 by 2050."

More than 20 countries including Japan and France, which depends heavily on nuclear energy, as well as the UAE, which is hosting COP28, endorsed the declaration.

But there have been objections to the declaration.

An international nongovernmental organization issued a statement noting that nuclear power is not only unstable and dangerous but also economically unreasonable as a source of energy.

It criticizes world leaders for having failed to learn lessons from the failures of the nuclear power industry in recent years.

The group stressed the need to promptly abolish the use of fossil fuels to tackle global warming.