Any hope for Congress to reconvene with a sense of bipartisanship was quickly erased Wednesday morning as Senate Minority Leader Mitch McConnell (R-Ky.) and House Speaker John A. Boehner (R-Ohio) sharply criticized the announcement of a new climate deal between the United States and China.

McConnell made his comments during a morning coffee with 10 newly elected Republican senators in his office off the Senate floor. As his new colleagues stood beaming, McConnell was asked by reporters whether he planned to shift the Senate to the political middle in hopes of reaching accord with President Obama and Democrats.

“The president continues to send a signal that he has no intention of moving toward the middle,” said McConnell, who is in line to become the new Senate majority leader in January. “I was particularly distressed by the deal he’s reached with the Chinese on his current trip, which, as I read the agreement, it requires the Chinese to do nothing at all for 16 years, while these carbon emission regulations are creating havoc in my state and other states across the country.”

In his initial reaction, McConnell said, “This unrealistic plan that the president would dump on his successor would ensure higher utility rates and far fewer jobs.”

Boehner denounced the agreement as “the latest example of the president’s crusade against affordable, reliable energy that is already hurting jobs and squeezing middle-class families.”

The speaker, who will preside over an increased GOP majority when the new Congress convenes, charged in a statement that Obama “intends to double down on his job-crushing policies no matter how devastating the impact,” and he pledged that Republicans would continue to make blocking Obama’s energy policies a priority for the rest of his term.

Top administration officials made it clear Wednesday the president would pursue some of his top priorities despite GOP opposition. Speaking to reporters on a press call Wednesday, Environmental Protection Agency administrator Gina McCarthy said Obama has emphasized the importance of curbing greenhouse gas emissions linked to climate change for months.

“The president has been very clear in the direction in he is moving,” McCarthy said. “He is not changing at all.”

While there is little lawmakers can do to block the U.S.-China climate agreement McConnell’s aides have already started investigating ways they could block or delay implementation of the EPA’s proposed rule to limit greenhouse gas emissions from existing power plants, which is set to become final next June. Rather than pushing for an outright reversal of the rule before it’s finalized, according to individuals familiar with these deliberations, Senate Republicans are looking at passing language that would give states the option of not complying with the EPA mandate until litigation on the issue is resolved, or that would bar federal authorities from enforcing the rule.

“You can issue all the executive orders you want. If you don’t have any money to enforce them, they don’t go very far,” said Rep. Tom Cole (R-Okla.) “We’re going to be pretty aggressive in using the power of the purse.”

McConnell’s home state of Kentucky is heavily dependent on its coal industry, and he made his criticisms of the Obama administration’s carbon emission and climate change policies central themes of his reelection campaign. McConnell handily won his race in he Nov. 4 midterm elections.

“I would welcome the president moving to the middle,” he added. “I’ve said before I hope we can do some business on trade and maybe tax reform. First indications have not been helpful.”

McConnell said he was especially pleased to see such a large class of incoming Republican senators and noted that two more may soon join up once results are finalized in Alaska and Louisiana.

Other Republicans joined McConnell and Boehner in trashing the deal. Sen. James M. Inhofe (R-Okla.), who is widely expected to assume the chairmanship of the Senate Environment and Public Works Committee in January, called the pledges by Obama and Chinese President Xi Jinping “hollow and not believable,” and he suggested that the agreement was tilted in China’s interest.

“The United States will be required to more steeply reduce our carbon emissions while China won’t have to reduce anything,” Inhofe said.

Congressional Democrats welcomed the agreement. House Minority Leader Nancy Pelosi (D-Calif.) said it represents “a commitment to confronting climate change with the seriousness it requires,” and she expressed hope that it could help “avoid the worst effects of permanent climate change.”

“There is no excuse left for inaction,” she said in a statement. “No nation can escape the impact of climate change — nor can any nation shirk its responsibility to confront this shared challenge. We must come together and take bold and ambitious steps to avert the climate crisis before us.”

Rep. Rosa DeLauro (D-Conn.) praised the agreement as “a way to start to move forward to grab some traction” on the climate change issue. She dismissed concerns that the accord might spoil any hopes that Obama and congressional Republicans could work together on other issues.

“You know what? Election Day didn’t change Republicans’ view of trying to do in Barack Obama,” she said. “You don’t have an epiphany the day after the election. I suspect with an increased majority they’re just going to look for more ways to make sure he doesn’t succeed.”

Despite the Republican opposition, U.S. officials traveling with Obama said they were confident that the president possesses the authority to set the new climate targets without additional authorization from Congress.

The Republican criticism came hours after Obama and Xi announced a far-reaching deal Wednesday to limit greenhouse gases, with China committing for the first time to cap carbon emissions and Obama unveiling a plan for deeper U.S. emissions reductions through 2025.

China, the world’s biggest emitter of greenhouse gases, pledged to cap its rapidly growing carbon emissions by 2030, or earlier if possible. It also set a daunting goal of increasing the share of non-fossil fuels to 20 percent of the country’s energy mix by 2030.

Obama announced a target to cut U.S. emissions 26 to 28 percent below 2005 levels by 2025, the first time the president has set a goal beyond the existing 17 percent target by 2020.

Independent experts said Wednesday that the U.S. could likely achieve its 2025 target if the administration continued to exercise its executive authority aggressively.

“It’s very doable,” said Kevin Kennedy, who directs the World Resources Institute’s U.S. Climate Initiative. “It’s not going to be easy, by any means.”

But Kennedy and others said it would only come to fruition if a like-minded politician succeeded Obama in the Oval Office. “It is based on assuming the next president continues an aggressive path,” said Gene Karpinski, president of the League of Conservation Voters.

The announcement capped a trip that also resulted in steps to cut tariffs on technology products, adopt warning measures to reduce the chance of accidental military conflict, and ease visas.

The two countries together account for about 45 percent of the world’s greenhouse-gas emissions, and their commitments are likely to energize talks underway to set new post-2020 targets when climate negotiators meet in Paris in December of next year. “The announcement provides a real shot of momentum for international climate negotiations,” one administration official said before the Obama-Xi announcement.

“We have a special responsibility to lead the global effort against climate change,” Obama said of the two nations at a joint news conference. “Today, I am proud we can announce a historic agreement.”

Meeting the goals will be difficult for both countries.

China completes a new coal plant every eight to 10 days, and while its economic growth has slowed, it is still expanding at a brisk rate of over 7 percent.

The scale of construction for China to meet its goals is huge even by Chinese standards. It must add 800 to 1,000 gigawatts of nuclear, wind, solar and other zero-emission generating capacity by 2030 — more than all the coal-fired power plants that exist in China today and close to the total electricity generating capacity of the United States.

To meet its target, the United States will need to double the pace of carbon pollution reduction from 1.2 percent per year on average from 2005 to 2020 to between 2.3 and 2.8 percent per year between 2020 and 2025.

China’s announcement is the culmination of years of change in attitudes among Chinese now fed up with dire levels of pollution that a study in the British medical journal the Lancet blamed for 1.2 million premature deaths in 2010 alone. China has cap-and-trade pilot programs in five provinces and eight cities. It is also the world’s largest investor in solar and wind energy.

Moreover, it has barred coal-plant construction in some regions. Such construction has dropped from more than 90 gigawatts in 2006 to 36.5 gigawatts in 2013, according to the World Resources Institute.

The joint climate announcement could undercut U.S. critics who have said that limiting greenhouse gases is pointless while China refuses to join such efforts. And it could quiet those in China who have argued that carbon emissions should be measured on a per capita basis or by improvements in energy intensity.

“It is imperative that these two countries — the world’s largest emitters of greenhouse gases — show real leadership. This is an important start,” said Phil Sharp, president of Resources for the Future. “Agreements like this are more important than they might appear at first glance, because in both countries there are political factions that justify inaction by pointing at the failures of the other country.”

Obama administration officials called the climate agreement a “historic step” that came together after months of negotiations, beginning when Secretary of State John F. Kerry raised the subject on a trip to Beijing in February. Obama followed up with a letter to Xi in the spring and met with Vice Premier Zhang Gaoli during the U.N. General Assembly in September. Chinese officials expressed interest in pursuing a deal that could be completed ahead of the ­Asia-Pacific Economic Cooperation meetings here this week, administration aides told reporters in a background briefing Wednesday.

Whether Obama’s target can be set now and achieved technologically — or enforced years after he leaves office — remains unknown.

Around the globe, the pact was widely praised. Leaders of the European Union, which last month pledged a 40 percent reduction in emissions by 2030, said the new commitments by China and the United States provided an important boost to negotiations on a global climate treaty in late 2015.

“These two crucial countries have today announced important pathways towards a better and more secure future for humankind,” said Christiana Figueres, the European Union’s top official on climate change.

A second Obama administration official said that it is uncertain whether other countries will seek to join the United States and China in pursuing new standards.

“Climate negotiations have been fraught for 20 years,” this official said. “There are 190-plus countries in these tough negotiations, and it’s not like they will all fall into place in five minutes. But this a really important step.”

Earlier, the United States and China reached agreements designed to defuse tensions over international trade and military maneuvers, even as both leaders courted other Asian nations attending the APEC forum in Beijing to join separate trade pacts.

Chinese and American trade negotiators agreed Tuesday to eliminate tariffs on $1 trillion a year of global sales of information and communications technology, including dozens of high-tech products such as GPS devices, medical equipment and game consoles. U.S. Trade Representative Michael Froman called the deal a “breakthrough” that could boost trade and create jobs.

The agreement now goes to the World Trade Organization, where 52 nations must approve. If they do, it would be the first major WTO agreement since 1996.

The deal would benefit U.S. companies seeking greater access to China as well as U.S. and Chinese companies with plants in China aimed at making products for the American market.

The APEC summit also has provided a venue for high-level encounters between heads of state. Obama held his first face-to-face conservations with Russian President Vladi­mir Putin since June, seeking to make headway on the conflict in Ukraine, the civil war in Syria and negotiations over Iran’s nuclear program. The two leaders spoke three times, for a total of 15 to 20 minutes, on the sidelines of the APEC meetings.

Nakamura reported from Beijing. Joby Warrick in Washington contributed to this report.