US President Barack Obama on Saturday hailed the landmark climate accord reached in Paris as strong and historic, calling it the best chance to save the planet from the effects of global climate change.

"Today the American people can be proud because this historic agreement is a tribute to American leadership. Over the past seven years, we've transformed the US into the global leader in fighting climate change," Obama said.

He said the accord shows what is possible when the world stands as one, adding: "This agreement represents the best chance we have to save the one planet that we've got."

Speaking at the White House hours after the deal was completed, Obama said that "no agreement is perfect, including this one," and that negotiations that involve nearly 200 nations are always challenging.

"Even if all the initial targets set in Paris are met, we'll only be part of the way there when it comes to reducing carbon from the atmosphere," Obama added.

Obama has made combating global climate change a top priority of his presidency but has encountered stiff resistance to his proposals from Republicans in Congress.

Republican Jim Inhofe, a global warming skeptic who heads the Senate Environment and Public Works Committee, said the climate deal was "no more significant to the United States" than the 1997 Kyoto Protocol, the last major climate deal.

Unlike the Kyoto pact, forged with Democratic President Bill Clinton in office, the Paris agreement will not be a fully legally binding treaty, which would almost certainly fail to pass in the U.S. Congress.

Clinton's White House successor, George W. Bush, concluded that the Kyoto pact was giving big emerging economies such as China and India a free ride, and would cost U.S. jobs. Having signed the deal, Washington never ratified it.

"Senate leadership has already been outspoken in its positions that the United States is not legally bound to any agreement setting emissions targets or any financial commitment to it without approval by Congress," Inhofe said.

Besides Inhofe, few Republicans voiced their opinions on the deal.

However, globally there were several reactions coming thick and fast from business leaders to politicians.

In his comments, EU Commission president Jean-Claude Juncker said: "Today the world is united in the fight against climate change. Today the world gets a lifeline, a last chance to hand over to future generations a world that is more stable, a healthier planet, fairer societies and more prosperous economies. This robust agreement will steer the world towards a global clean energy transition."

US Secretary of State John Kerry declared it as a tremendous victory "for all of our citizen, not for any one country, or any one bloc, but for everybody here who has worked so hard to bring this across the finish line."

He said it was a victory for all of the planet and for future generations.

"We have set a course here. The world has come together around an agreement that will empower us to chart a new path for our planet, a smart and responsible path, a sustainable path," added Kerry.

Hillary Clinton, the presidential hopeful, said: "We cannot afford to be slowed by the climate sceptics or deterred by the defeatists who doubt America's ability to meet this challenge. That's why as president, I will make combating climate change a top priority from day one, and secure America's future as the clean energy superpower of the 21st century."

In his remarkes, UK Prime Minsiter David Cameron said: "The talks at the COP21 conference in Paris have culminated in a global deal, with the whole world now signed up to play its part in halting climate change."

"In other words, this generation has taken vital steps to ensure that our children and grandchildren will see that we did our duty in securing the future of our planet. What is so special about this deal is that it puts the onus on every country to play its part," he added.

Welcoming the historic accord, World Bank Group president Jim Yong Kim said: "The world has come together to forge a deal that finally reflects the aspiration, and the seriousness, to preserve our planet for future generations."

"We called for strong ambition, for remarkable partnerships, for mobilization of finance, and for implementation of national climate plans. Paris delivered. Now the job becomes our shared responsibility," he added.

International Energy Agency (IEA) dubbed the agreement as nothing less than a historic milestone for the global energy sector. It will speed up the transformation of the energy sector by accelerating investments in cleaner technologies and energy efficiency, it stated.

Lauding the agreement, India's Environment Minister Prakash Javadekar said: "We have opened a new chapter of hope in the lives of 7 billion people on the planet. We have (the planet) on loan from future generations. We have today reassured these future generations that we will all together give them a better earth."

His German counterpart Barbara Hendricks said: "For the first time all the countries of the world are together on the path to save the planet ... we fought for a long time and today we've reached a solid agreement. It is a historic turning point."

Philippe Defosses, the director of French Pension Fund ERAFP said the Paris agreement marks a tipping point.

"Going forward the world has a shared vision that will lead inexorably to investors moving away from fossil fuels and towards a future powered by low carbon energy. Investors will encourage every country keen to build a sustainable economy to develop a long-term low-emissions development strategy, including carbon pricing schemes, so that investors know ambition levels over the short, medium- and long-term," he noted.

Jack Gerard, the president and CEO of American Petroleum Institute, said: "America's private sector has already taken the lead on reducing greenhouse gas emissions, even as we increase economic activity and domestic energy production to keep energy reliable and affordable for consumers. Our success is driven, not by government mandate or legislative fiat, but through innovation, investment and entrepreneurial spirit."

"We will closely scrutinize the COP 21 agreement to see how it references the U.S. model of reducing emissions through technological innovation and increased use of natural gas," he added.

Jeffrey Sachs, the director of the earth institute at Columbia University said the diplomats have done their job: the Paris Agreement points the world in the right direction, and with sophistication and clarity. It does not, however, ensure implementation, which necessarily remains the domain of politicians, businessmen, scientists, engineers, and civil society.

The GE lauded the governments on this important milestone and their joint efforst to save the earth. "We look forward to reviewing details of agreement. GE will continue to lead business in combating climate change by working across sectors to drive innovation, invest in new technologies and scale new business models," said its spokesperson.-Reuters