The world's fourth-largest polluter, India, hopes to join the Paris climate change deal by the end of the year.
Prime Minister Narendra Modi announced this on Tuesday after a meeting with United States President Barack Obama in Washington.
Although the Indian Prime Minister stopped short of making a firm commitment, it was still hailed as an important development from a country that has until now maintained that environmental concerns should not slow economic growth.
White House press secretary Josh Earnest told reporters the Indian pledge "represents a more ambitious goal than India had previously laid out in terms of signing onto the agreement". "So we obviously welcome that announcement from the Indian government," he said.
Mr Brian Deese, a White House senior adviser on climate and energy policy, said: "I think we are better positioned than we ever have been to reach the goal of 55 per cent of emissions and 55 countries by the end of this year, and I think this statement should provide significant additional momentum towards this global push."
The Paris accord, which seeks to limit global warming to less than 2 deg C above pre-industrial level, will go into effect 30 days after 55 countries representing 55 per cent of all greenhouse gas emissions ratify it. India accounts for just over 4 per cent of the world's greenhouse gas emissions, and if it joins, it will be the 46th country to do so and take the global tally to 54.7 per cent.
The announcement on climate change was among agreements unveiled on Tuesday. The other pacts were for areas such as defence and economic cooperation.
Besides climate change, analysts were also looking for progress in civil nuclear cooperation and non-proliferation during Mr Modi's visit.
On that front, the two sides said on Tuesday that US-based Westinghouse Electric had started work on six nuclear reactors in India - the first major development from a watershed civil nuclear cooperation deal signed more than a decade ago.
Stumbling blocks like financing are still in the way before the promise of the deal is fully realised. But both sides agreed to conclude contractual arrangements by next year.
The day's developments went some way towards addressing concerns that the two sides might stop looking for new commitments now that Mr Obama is on his last lap.
In brief remarks after an hour- long meeting in the White House, Mr Obama and Mr Modi kept their focus on the growing friendship between the two nations.
"We continue to discuss a wide range of areas where we can cooperate more effectively in order to promote jobs, promote investment, promote trade and promote greater opportunities for our people, particularly young people, in both of our countries," said Mr Obama.
Mr Modi, in turn, paid tribute to the joint leadership role on global issues the two countries are playing: "We have been working shoulder to shoulder and I feel proud that we are not just two friends and two countries that are working together. We are proud of the leadership role that we have taken on and we will continue to do so."