America's new power plant regulations, due for release on Monday, could unlock stalled negotiations for a global deal on climate change, the United Nations' top climate official said.
Christiana Figueres, the UN's top climate change official, said she expects the new power plant rules could spur other big emitters - such as China and India - to begin taking action on climate change and move forward on reaching a deal by the 2015 deadline.
The Environmental Protection Agency will roll out the new rules on Monday - the most significant action taken under any president to deal with climate change.
Figueres said in a statement on Sunday she believed the rules would send "a good signal to nations everywhere" that America is serious about dealing with the threat of climate change.
The new EPA could cut carbon pollution from the country's power plants by up to 25% by 2020 - tackling the biggest source of the greenhouse gas emissions that cause climate change.
The regulations would put America within range of the commitment Obama made at the Copenhagen climate summit in 2009, to cut US emissions 17% from 2005 levels by 2020.
But the EPA regulations could have an even more important knock-on effect. Figueres added: "I fully expect action by the United States to spur others in taking concrete action".
That is an important consideration for Obama, domestically and internationally. One of the standard Republican arguments against the power plant rules is that they will do almost nothing to reduce global greenhouse gas emissions - and that America will be making sacrifices on its own.
Those arguments would be less effective if China, India and Brazil - which have all been moving to reduce their emissions - step up their efforts in response to the EPA rules.
European Union diplomats and those who follow the international negotiations for a global climate deal have been looking to Obama to play a leading role on climate change since he entered the White House in January 2009
Those hopes withered after Congress failed to pass climate change legislation in 2010.
Obama's decision to circumvent Congress and use his executive authority to achieve emissions cuts have revived expectations, said Saleemul Huq, a fellow at the International Institute for Environment and Development.
"President Obama's move on restricting pollution from power plants in the US in the face of strong opposition shows that he is for now serious about tackling climate change. This will bring new energy to the international negotiations," he said in an email.
The EPA rules are well-timed in terms of the negotiations for a global climate change deal. Analysts said they could provide momentum to the final stages of reaching an agreement in Paris in late 2015.
"A level of ambition that helps the United States meet its short-term climate goal (reducing emissions 17% below 2005 levels by 2020) and that lays out a longer-term trajectory for even deeper cuts will send a powerful signal to the rest of the world," Michael Obeiter, a fellow at the World Resources Institute, wrote in a blog post. "It will show that the country is prepared to do its part in helping to avoid the worst impacts of a changing climate."
Obama is conscious of those expectations. He said in a speech last week to West Point cadets that America needed to show it was serious about climate change, if it wanted the other big emitters to move.
"American influence is always stronger when we lead by example," Obama said. "We cannot exempt ourselves from the rules that apply to everyone else. We can't call on others to make commitments to combat climate change if a whole lot of our political leaders deny that it's taking place."