US President Joe Biden flies into UN climate talks in Egypt on Friday armed with major domestic achievements against global warming but under pressure to do more for countries reeling from natural disasters.
Biden will only spend a few hours at COP27 in the Red Sea resort of Sharm el-Sheikh, three days after US midterm elections that have raised questions about what the result could mean for US climate policy.
The US leader's climate agenda was given a major boost this year when Congress passed a landmark spending bill, the Inflation Reduction Act, which includes $369 billion for clean energy and climate initiatives.
But at COP27, talk has been dominated by the need for wealthy nations to stop stalling on helping developing countries green their economies and prepare for future impacts -- as well as calls to provide financial help for the damage already being caused by climate-induced catastrophes.
"The world needs the United States to be a climate leader in our fight for climate justice," prominent Ugandan climate activist Vanessa Nakate told AFP.
"The message is for President Biden to stand with the people on the planet and the coming generations," said the 25-year-old Goodwill Ambassador for UNICEF.
Biden is attending COP27 three days after 100 other world leaders addressed the summit.
A senior US official said Biden was heading to Egypt "with historic momentum" on the back of the spending bill and his goal to cut greenhouse gas emissions by up to 52 percent by 2030 from 2005 levels.
So far at the Egypt talks, US climate envoy John Kerry has presented a public-private partnership aimed at supporting the transition to renewable energy in developing nations and based on a carbon credit system.
The plan has been panned by activists wary of firms using these to "offset" their carbon emissions.
- Climate-sceptic Republicans -
Biden also may have a chance to revive cooperation with China when he meets President Xi Jinping during G20 talks next week, with another US official saying he would seek to discuss how to "advance our work together on climate change".
Beijing cut off climate talks with Washington after US House Speaker Nancy Pelosi visited Taiwan in August.
Cooperation between the world's two biggest polluters has been crucial to global efforts to limit global warming to 1.5 degrees Celsius.
But with Republicans apparently poised to retake the House of Representatives, part of Biden's climate agenda could take a hit. Democrats have a chance to retain the Senate.
Biden pledged to contribute $11.4 billion to a $100 billion per year scheme through which rich countries will help developing ones transition to renewable energies and build resilience against climate change.
But Democrats would have to rush it through Congress before climate-sceptic Republicans take office in January.
"We're going to be pressing for passage of the appropriations bills," US lawmaker Kathy Castor, who chairs a special climate crisis committee in the House, told AFP.
"Hopefully Republicans in the Congress will not block it," she said.
- 'Loss and damage' -
The United States has also for years resisted attempts to establish a "loss and damage" fund in which rich polluters would compensate developing nations for the destruction from climate-related disasters.
Emerging countries successfully put the issue on the official COP27 agenda and fraught negotiations are likely before the talks end on November 18.
Biden will also use the trip to meet with Egyptian President Abdel Fattah al-Sisi and discuss the human rights situation in the country, where the case of jailed dissident Alaa Abdel Fattah was raised by other leaders earlier this week.
Ahead of his trip, the White House expressed "deep concern" for the jailed British-Egyptian activist, who is on a hunger strike.
After COP27, Biden will head to an ASEAN regional summit in Cambodia at the weekend before travelling to Indonesia for G20 talks.