US President Joe Biden arrived at 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 spend only a few hours at COP27 in Sharm el-Sheikh, three days after US midterm elections that have raised questions about what the result could mean for US climate policy.

The lightning visit to Egypt marks the start of a week-long trip abroad that will also take him to an ASEAN regional summit in Cambodia at the weekend, before he travels to Indonesia for G20 talks.

Climate action in the United States -- the world's second biggest emitter -- 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.

Global warming "is an urgent crisis", Biden said as he met Egyptian President Abdel Fattah al-Sisi on the sidelines of COP27, where he said he would address human rights in the country with his host.

Biden, who was due to deliver a speech later, skipped a two-day summit of about 100 world leaders at COP27 that coincided with the US election earlier this week.

'Historic polluter'

New research shows just how dauntingly hard it will be to meet the goal of capping global warming at 1.5 degrees Celsius above preindustrial levels -- requiring emissions to be slashed nearly in half by 2030.

The new study -- published on Friday in the journal Earth System Science Data -- found that CO2 emissions from fossil fuels are on track to rise one percent in 2022 to reach an all-time high.

COP27 talks have been dominated by the need for wealthy polluters to stop stalling on helping developing countries green their economies and prepare for future impacts -- alongside calls to provide financial help for the catastrophic damage already apparent.

Calling out the United States as "the historic polluter", Mohamed Adow, founder of the think tank Power Shift Africa, said Washington has been an obstacle to the establishment of a "loss and damage" fund.

"So our test for Biden ... is, will he actually set out US commitment in providing effective support on loss and damage for the vulnerable countries?" Adow said.

The United States agreed to have the issue discussed at COP27, with developing countries least responsible for planet-heating emissions seeking what amounts to reparations from rich polluters to cope with accelerating climate impacts.

Climate-skeptic Republicans

Germany's climate envoy, Jennifer Morgan, told reporters that Biden's attendance at COP27 was a "very good sign" that reassures other countries that "the United States at the highest level takes this issue incredibly seriously".

White House National Security Adviser Jake Sullivan said Biden will "underscore the need to go further, faster, to help the most vulnerable communities build their resilience" and push major economies to "dramatically" cut emissions.

US climate envoy John Kerry presented this week a public-private partnership aimed at supporting the transition to renewable energy in developing nations and based on a carbon credit system.

But the plan has been panned by activists wary of firms using these to "offset" their carbon emissions.

The White House announced Friday plans to require federal contractors to set targets to reduce their emissions in line with the Paris Agreement.

It also aims to step up efforts to cut methane emissions -- a major contributor to global warming -- with a "Super-Emitter Response Programme" that would require companies to act on leaks reported by "credible" third parties.

Biden has also pledged to contribute $11.4 billion to a $100 billion per-year-scheme through which rich countries will help developing nations transition to renewable energies and build climate resilience.

But Democrats may be running out of time to honour that as control of the House of Representatives appears poised to shift to the Republicans from January in the wake of this week's mid-term elections.

"We're going to be pressing for passage of the appropriations bills," US lawmaker Kathy Castor, who chairs the climate crisis committee in the House, told AFP.

© Agence France-Presse