Biden wants to send more climate cash abroad. Republicans want a say.

President Joe Biden made fresh pledges Thursday to bolster the United States' international climate spending against a harsh reality: Republicans stand in the way of the promises he's making to nations most vulnerable to rising temperatures.

Biden's $1 billion commitment to the Green Climate Fund, a major international climate aid vehicle, sought to burnish U.S. credibility after former President Donald Trump and congressional Republicans had zeroed out U.S. contributions for the program. Biden also said he'd work with Congress to approve $500 million over five years to combat rainforest deforestation through Brazil's Amazon Fund program.

"The impacts of climate change will be felt the most by those who have contributed the least to the problem, including developing nations," Biden told the virtual gathering of the Major Economies Forum on Energy and Climate, which included leaders of Canada, Mexico, Germany, Egypt, Australia and the European Commission, as well as United Nations Secretary-General António Guterres.

"As large economies we must support these economies," Biden said. "The fund is critical in ways to helping developing nations that they can't do now — but it should not be the only way."

Yet the announcements came just a day after House Speaker Kevin McCarthy launched an all-out assault on the heart of Biden's domestic climate agenda — a sign of the divisions at home that continue to bedevil the United States' efforts lead the world in combating the planet's warming.

McCarthy proposed legislation Wednesday that would strip billions of dollars of domestic clean energy incentives in return for raising the U.S. borrowing limits to avoid an economically crippling debt default. McCarthy's negotiating tactics signal that Republicans are unlikely to back increased climate funding of any sort, especially given his party has historically opposed international climate spending.

Republican positioning imperils Biden's goal of increasing international climate finance to $11 billion annually by 2024 and threatens to throttle whatever goodwill rich nations earned at last year's U.N. climate talks, in which delegates agreed to create a "loss and damage" fund to pay poorer nations for irreparable climate damage. That fund is not yet operational, and Republicans criticized its creation at last November's talks in Sharm el-Sheikh, Egypt.

The United Arab Emirates, which is hosting this year's climate talks, has said finance will be a central focus.

"In order for us to connect course we have to come to terms with some realities and we have to come with a robust understanding what it takes to put this back on the right track," Sultan Ahmed al Jaber, the president of the UAE-hosted talks, said at an event in Washington, D.C., last week. "And it's all centered around making finance and capital available."

The Major Economies Forum was first launched in 2009 and now includes more than two dozen countries that produce 80 percent of the world's greenhouse gas emissions and GDP. It was the first meeting since the creation of the loss and damage fund — and some countries have openly questioned how much work wealthy nations are doing to bring that fund into fruition.

Developing nations have reasons to be skeptical. Rich countries still have not delivered on a 2009 vow to distribute $100 billion in climate finance annually by 2020. And even with Biden's most recent contribution to the Green Climate Fund, the United States — the world's largest economy and the top historical driver of climate change — is still falling short of former President Barack Obama's initial $3 billion promise in 2014. In contrast, some other countries have even begun making new commitments.

The effort, however, indicates that the Biden administration is responding to calls from developing nations to deliver more money to help them cope with the effects of the changing climate.

The Biden administration has also emphasized finance efforts that circumvent the need for congressional action. On Thursday, Biden announced a new "Methane Finance Sprint" to raise at least $200 million from public and philanthropic sources by the start of the annual U.N. climate talks in November. Biden said the effort would help the U.S. and other countries reach goals to slash methane emissions 30 percent this decade.

His administration has leaned on institutions like multilateral development banks such as the World Bank to fight climate change, seeing it as a way to augment public spending by mobilizing private sector dollars. The Bank concluded its spring meetings last week and laid out an "evolution roadmap" to engage on climate change.

"Certainly with this Congress, we're not going to produce that money. But we're not anyway," special climate envoy John Kerry said at an event in Washington, D.C., last week as the World Bank meetings were taking place. "In order to do what we need to do we need to be investing — not spending, investing — $4.5 trillion a year for the next 30 years."