SHARM EL-SHEIKH, EGYPT -- U.S. President Joe Biden, speaking Friday at an annual international summit on climate change, urged world leaders to "double down" on their resolve to fight global warming, saying Russia's invasion of Ukraine reinforces the need to phase out fossil fuels.

"We can no longer plead ignorance to the consequences of our actions, or continue to repeat our mistakes," Biden said.

The president's brief attendance at the United Nations climate conference, known as COP27, was largely a victory lap as he emphasized new spending on clean energy initiatives that will "change the paradigm" for the United States and the rest of the world.

But Biden glossed over how he's pushed for more oil and gas production to bring down costs that have been politically troublesome at home, and fueled the invasion of Ukraine by allowing Russia to fetch higher prices for its energy exports.

"This gathering must be the moment to recommit our future and our shared capacity to write a better story for the world," Biden said.

Biden spent just three hours in Egypt, including a meeting with the country's autocratic leader, President Abdel-Fattah el-Sissi, before continuing on an around-the-world trip. He arrived Saturday morning for his next stop in Cambodia, where he would participate in a meeting of Southeast Asian leaders, and then Indonesia for the annual Group of 20 summit of the world's largest economies.

Biden left Washington late Thursday buoyed by a stronger-than-expected showing by the Democratic Party in Tuesday's midterm elections, earlier congressional passage of the largest climate investment in U.S. history and Russian military setbacks on the Ukrainian battlefield.

At the climate conference, Biden discussed a new supplemental rule that will crack down on methane emissions, expanding on a similar regulation his administration released last year. Methane is a potent greenhouse gas that contributes significantly to global warming.

Biden also spotlighted one of his key domestic successes -- the Democrats' massive health care and climate change bill known as the Inflation Reduction Act.

The U.S. commitment of some US$375 billion over a decade to fight climate change gives Biden greater leverage to press other nations to fulfill their pledges to reduce greenhouse gas emissions and shift the global economy toward cleaner energy sources.

"The United States government is putting our money where our mouth is," he said.

Biden said the spending, part of broader economic legislation he signed into law this year, will ensure the U.S. hits its target for reducing emissions by 2030.

The president was in a far different position from last year's gathering, which came about during a particularly unhappy stretch in the bill's tortuous path to passage.

That summit resulted in additional global commitments to meet temperature targets agreed to in the Paris Climate Accord, which Biden rejoined after his predecessor, Donald Trump, pulled the U.S. from the deal.

Jennifer Morgan, Germany's special climate envoy, said Biden "made it very clear that the climate crisis is a major top priority for the United States domestically in getting laws passed, internationally in partnership with other countries."

She said it contributed "a positive energy coming into this conference."

Biden argued that "good climate policy is good economic policy," and he called on all major emitting countries to "align their ambition" to the international goal of trying to limit future global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit), according to the White House.

But even with these fresh efforts, America and the world have a long way to go to meet emissions targets that scientists hope will contain global warming. And the political will for more investment is shrinking.

Biden acknowledged that climate crises are "hitting hardest those countries and communities that have the fewest resources to respond and recover," a reference to a leading issue at the summit.

Known as "loss and damage," it involves asking rich countries like the United States, the top historic polluting nation, to pay what are essentially reparations for damages caused to poorer vulnerable nations that don't emit much heat-trapping carbon dioxide.

Biden announced in his speech the U.S. would contribute US$150 million "as a down payment" to initiatives to help Africa adapt to the changing climate, but that did not satisfy concerns.

"We would like for the U.S. to step up their game on loss and damage," Sierra Club President Ramon Cruz said. "We would of course like to see more commitment to that."

The U.S. in the past has opposed even talking about the issue, but has softened its stance and agreed to discussions. Biden's climate envoy, John Kerry, has mentioned the issue in speeches. However, the U.S. doesn't want liability to be part of any deal. In addition, Congress and the public have been reluctant to embrace many types of climate aid -- and this is the most controversial type.

The lack of congressional support has tied Biden's hands, said Alice Hill, who worked on climate issues in President Barack Obama's administration.

Even though Biden announced other initiatives, she said, "he couldn't deliver what the developing world most wants: enough money to adapt to climate extremes."

Prospects for a significant breakthrough are further dampened as major emitters such as China and India are sending less-senior delegations to the conference. Biden administration officials have tried to lower expectations for results and instead cast the meeting as a return to U.S. leadership on the issue.

Biden left Washington with votes still being tallied in key races that will determine political control of Congress. Still, the president was buoyed as Democrats performed stronger than expected.

After arriving in Egypt, Biden met with el-Sissi. The leaders discussed climate, human rights and the U.S.-Egypt defence partnership, among other issues, the White House said. The Egyptian leader proactively and publicly raised human rights with Biden before their one-on-one meeting, and did so again in the private portion of the sit-down.

"We are very keen on improving this part," said el-Sissi, who emphasized that Egypt had launched a national strategy on human rights. For his part, Biden said the U.S. and Egypt are "continuing our dialogue on human rights" and added that he hopes they'll be "closer and stronger in every way."

During the meeting, Biden and U.S. officials raised the case of imprisoned Egyptian pro-democracy activist Alaa Abdel-Fattah, whose family has said is undergoing an undefined medical intervention amid a hunger strike.

Jake Sullivan, the national security adviser, said Biden directed his aides to work with the Egyptians on that case and others, and said officials had "intense consultations on that case" while in Sharm El-Sheikh but declined to elaborate further. U.S. did not have an update on his condition, considering the family and the Egyptian government had conflicting accounts.

"This is a circumstance where it's not trust but verify, it's verify," Sullivan told reporters on Air Force One as Biden traveled to Phnom Penh. "And we've not been able to do that."

Sullivan added: "We are doing everything we can to secure his release."

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Kim reported from Phnom Penh, Cambodia. AP writers Seth Borenstein in Sharm el-Sheikh, Egypt, and Chris Megerian, Aamer Madhani, Matthew Daly and Darlene Superville in Washington contributed to this report.