Some of the world's biggest companies ranging from Coca-Cola to Walmart announced pledges to combat climate change Monday as part of the Obama administration's efforts to generate momentum for a global climate deal.

The 13 American companies making new commitments are Alcoa, Apple, Bank of America, Berkshire Hathaway Energy, Cargill, Coca-Cola, General Motors, Goldman Sachs, Google, Microsoft, PepsiCo, UPS and Walmart. Together they generated $1.3 trillion in revenue in 2014 and have a combined market capitalization of $2.5 trillion.

"Today's announcements are only the beginning. This fall, the Obama administration will release a second round of pledges, with a goal of mobilizing many more companies to join the American Business Act on Climate Pledge," the White House said.

The announcement is part of a broader effort to secure a pact at United Nations-hosted negotiations in Paris beginning in late November that would govern greenhouse gas emissions reductions beyond 2020. Countries such a deal would help prevent a 2 degree Celsius global temperature rise by 2100, though experts contend the gap between political will and how much countries would need to slash emissions make reaching that goal unlikely.

"Our engagement with these companies today is around their commitment to supporting a strong outcome in Paris," White House adviser Brian Deese told reporters in a conference call. "This is about demonstrating the American business community's support for a strong outcome and demonstrating U.S. leadership."

The move comes as the Obama administration's signature climate regulation — limits to carbon emissions from power plants — nears finalization. The White House is expected to lean on big businesses to make the case for supporting the rule in the face of GOP and industry criticism that the regulation would raise energy costs and stunt the economy.

GOP attacks on whatever deal emerges from Paris also have been getting louder lately. The White House has hinted it believes it can use existing treaties and a non-binding emissions pledge to avoid having to send the deal through the Senate for ratification, but Senate Republicans will try to force President Obama to submit the accord through the upper chamber.

Deese wouldn't say whether the White House had encouraged the companies to lobby recalcitrant Republicans to support either the Paris process or the power plant rule.

Obama, as part of the U.N. climate process, said the United States would cut overall emissions at least 26 percent by 2025. But Republicans have questioned how his administration plans to achieve that mark, noting that existing and planned regulations leave the U.S. about 34 percent short, according to an analysis by the U.S. Chamber of Commerce that GOP lawmakers have increasingly cited.

Business commitments are likely part of that plan.

All told, the companies said they'd invest at least $140 billion in low-carbon technology and more than 1,600 megawatts of renewable energy on top of company-specific goals to halve greenhouse gas emissions and curb water use, the White House said. More commitments are expected at an October State Department event.

Coca-Cola said it would slash emissions by one-quarter by 2020. General Motors said it would reduce carbon and energy intensity one-fifth by 2020, compared with 2010 levels. UPS said it would cut emissions 20 percent by 2020, compared with 2007 levels.

Google said it hoped to power all its operations with renewable energy and that it would triple its purchases of renewable power by 2025. Microsoft said it would run all its data centers, offices, labs and manufacturing facilities on renewable power.

Investors also made commitments. Bank of America said it would increase its environmental business lending, investing, capital-raising, advising and financing to $125 billion by 2025, up from $50 billion. Goldman Sachs said would aim to power all its operations with renewable energy by 2020.

And Berkshire Hathaway said it would invest another $15 billion in clean energy to build on the $15 billion it already spent on the stuff through 2014. The company also said it would add 552 megawatts of new wind generation in Iowa through electric utility MidAmerican Energy Company and that it would shutter three-fourths of its coal-fired power in Nevada.