India 'bigger problem' than China on reducing carbon emissions: Michael Bloomberg

India poses a bigger problem than China when it comes to fighting climate change, particularly on reducing carbon emissions, Democratic presidential aspirant and former New York mayor Michael Bloomberg has said.

During his maiden appearance on a Democratic presidential primary debate in Las Vegas on Wednesday, Bloomberg said it was "ridiculous" of the Trump administration to take the US out of the 2015 Paris climate agreement, as he outlined his approach to tackling climate change.

"In all fairness, the Chinese have slowed down. It is India that is an even bigger problem, but it is an enormous problem. Nobody is doing anything about it," Bloomberg said in response to a question on climate change.

He was asked about his business which is heavily invested in China, the number one producer of carbon emissions in the world, and how far would he go to force Beijing to reduce those emissions and tackle the climate crisis.

"You're not going to go to war with them. You have to negotiate with them and we have seen how well that works with tariffs that are hurting us. What you have to do is convince the Chinese that it is in their interest as well, their people are going to die just as our people are going to die and we will work together," Bloomberg said in his response.

The billionaire and philanthropist, who announced his presidential run only this year, asserted that the US was making a difference.

"We are closing the coal-fired power plants. If we and for some of the rules on fracking so that they don't release methane into the air and into the water you will make a big difference but we are not going to get rid of fracking for a while and we frac incidentally not just natural gas, you frac oil as well," he said.

"Let's start at the beginning. If you're President, the first thing you do the first day is you rejoin the Paris agreement. This is just ridiculous for us to drop out," Bloomberg said, adding that America's responsibility is to be the leader in the world.

"And, if we don't, we are going to be the ones that get hurt just as much as anybody else and that's why I don't want to have us cut off all relationships with China because you will never solve this problem without China and India, western Europe and America," he said.

"The idea of China and their Belt and Road proposal is they are taking the dirtiest coal in the world mostly out of Mongolia and spreading it around the world," he said.

"It is clear they make it clear when you call them to Washington in the first 100 days if you continue you will suffer severe consequences because the rest of the world will impose terror of sand on everything you are selling because you are undercutting the entire economy," Biden said.

"It is time to exit the Paris Accord and time to pursue a new deal that protects the environment, our companies, our citizens, and our country," Trump had said, dampening global efforts to curb global warming.

"India makes its participation contingent on receiving billions and billions and billions of dollars in foreign aid from developed countries. There are many other examples. But the bottom line is that the Paris accord is very unfair, at the highest level, to the United States," Trump said.