By MICHAEL D. SHEAR

WASHINGTON — The Obama administration on Friday announced that it was not backing down from a confrontation with the coal industry and that it would press ahead with enacting the first federal carbon limits on the nation’s power companies.

The proposed regulations, announced at the National Press Club by Gina McCarthy, the administrator of the Environmental Protection Agency, are an aggressive move by Mr. Obama to bypass Congress on climate change with executive actions he promised in his inaugural address this year. The regulations are certain to be denounced by House Republicans and the industry as part of what they call the president’s “war on coal.”

In her speech, Ms. McCarthy unveiled the agency’s proposal to limit new gas-fired power plants to 1,000 pounds of carbon dioxide emissions per megawatt-hour and new coal plants to 1,100 pounds of carbon dioxide. Industry officials say the average advanced coal plant currently emits about 1,800 pounds of carbon dioxide per megawatt-hour.

“The president’s Climate Action Plan calls on federal agencies to take steady, sensible, and pragmatic steps to cut the harmful carbon pollution that fuels our changing climate, to prepare our communities for its unavoidable impacts, while continuing to provide affordable and reliable energy for all,” Ms. McCarthy said.

Opponents of the new E.P.A. rule quickly vowed to take measures to stop it. Senator Mitch McConnell, the Republican leader who is from coal-dependent Kentucky, promised to use his legislative skills to prevent the measure.

“The president’s decision today is an escalation of the war on coal and what that really means for Kentucky families is an escalation of his war on jobs and the Kentucky economy,” Mr. McConnell said. “I will file a resolution of disapproval under the Congressional Review Act to ensure a vote to stop this devastating E.P.A. rule.”

Ms. McCarthy also announced a yearlong schedule for an environmental listening tour — a series of meetings across the country with the public, the industry and environmental groups as the agency works to establish emissions limits on existing power plants — a far more costly and controversial step. Mr. Obama has told officials he wants to see greenhouse gas limits on existing and new power plants by the time he leaves office in 2017.

“We will respond to the threat of climate change, knowing that the failure to do so would betray our children and future generations,” Mr. Obama said in January. But he acknowledged that “the path toward sustainable energy sources will be long and sometimes difficult.”

On Friday, Ms. McCarthy said: “We have proven time after time that setting fair Clean Air Act standards to protect public health does not cause the sky to fall. The economy does not crumble.”

She also said: “The overwhelming judgment of science tells us that climate change is real, human activities are fueling that change, and we must take action to avoid the most devastating consequences. We know this is not just about melting glaciers. Climate change — caused by carbon pollution — is one of the most significant public health threats of our time. That’s why E.P.A. has been called to action. And that’s why today’s action is so important for us to talk about.”

The limits unveiled on Friday are a slightly more relaxed standard for coal plants than the administration first proposed in April 2012. Officials said the new plan, which came after the E.P.A. received more than 2.5 million comments from the public and industry, will give coal plant operators more flexibility to meet the limits over several years.

The rules on new power plants will soon face a 60-day public comment period, likely to be followed by intensive industry and environmental lobbying and possible court challenges. Officials said the rules could be finalized by the fall of 2014.

Once the rules are in place, coal power plants will be required to limit their emissions, likely by installing technology called “carbon capture and sequestration,” which scrubs carbon dioxide from their emissions before they reach the plant smokestacks. The technology then pumps it into permanent storage underground.

This article has been revised to reflect the following correction:

Correction: September 20, 2013

An earlier version of this article referred imprecisely to the amount of carbon dioxide emissions from the average advanced coal plant. It is 1,800 pounds of carbon dioxide per megawatt-hour, not 1,800 pounds of carbon dioxide per hour.