Although the nonbinding World Bank declaration is meant largely as a show of resolve ahead of a 2015 climate summit in Paris, it signals the broadest, most explicit effort to date of world leaders and financial institutions to push all nations to enact new taxes on old forms of energy. The declaration notes that governments can either directly tax carbon pollution or create market-based cap-and-trade systems, which force companies to buy government-issued pollution permits.

“The most powerful move that a government can make in the fight against climate change is to put a price on carbon,” said Rachel Kyte, the World Bank’s vice president of sustainability.

To many Republicans on Capitol Hill, such statements are anathema. In 2010, after Mr. Obama tried but failed in the face of conservative opposition to push a national cap-and-trade bill through Congress, victorious Republicans galvanized against the idea and launched campaigns against politicians who support carbon pricing. Mr. Obama in turn circumvented Congress and in June released a new Environmental Protection Agency regulation under his executive authority that requires states to submit their own plans to cut emissions — but does not tell them explicitly how to do so. Nonetheless, California and nine Northeastern states have already enacted cap-and-trade programs, and seven states — California, Maryland, Massachusetts, Oregon, Rhode Island, Vermont and Washington — signed on to the World Bank declaration.

In order to avoid more opposition from conservatives, Mr. Obama and other top administration officials no longer call publicly for a national price on carbon. But they have nonetheless signaled their support for international and state efforts. In his speech at the United Nations, Mr. Obama quoted the Democratic governor of Washington, Jay Inslee, who is urging other states to pass carbon pricing laws: “As one of America’s governors has said, ‘We are the first generation to feel the impact of climate change and the last generation that can do something about it.’ ”

The Obama administration has also enacted a policy signaling its readiness to price carbon should the politics of Congress ever shift: a metric it calls “the social cost of carbon,” designed to account for the cost of one ton of carbon dioxide pollution. Mr. Obama’s economists have determined the cost to be $37 a ton. Secretary of State John Kerry, a longtime advocate of government policy to fight climate change — and the chief author of the failed 2010 cap-and-trade bill in the Senate — last week told a meeting of the Major Economies Forum that “when it comes to climate change, we know exactly what it takes to get the job done.”