DUBAI: The US has pledged $3 billion to the Green Climate Fund, Vice President Kamala Harris said in Dubai at the UN COP28 climate summit.

The fund, with more than $20 billion in pledges, is the largest international fund dedicated to supporting climate action in developing countries.

The latest pledge, which Reuters was first to report, would be additional to another $2 billion previously delivered by the US.

Sources said the pledge was subject to the availability of funds. The politically divided US Congress needs to authorize the funding.

Harris announced the pledge in her address to the summit.

"Today I am also proud to announce a new $3 billion pledge to the Green Climate Fund which helps developing countries invest in resilience, clean energy, and nature-based solutions,” she said.

The fund's facilitators said in October that the current second round of replenishments had brought in about $9.3 billion in pledges to fund projects in climate-vulnerable counties between 2024 and 2027.

Even so, pledges so far represent a fraction of roughly $250 billion that developing countries would need every year by 2030 just to adapt to a warmer world, according to the UN. In addition to supporting climate adaptation, the fund also finances projects to help countries shift to clean energy.

Harris, who was representing the US at COP28 in place of President Joe Biden, was part of a US delegation that also includes climate envoy John Kerry and dozens of senior administration officials and cabinet members.

“It was important for both the president and vice president to ensure that a leader from the United States was at COP,” an official said, adding that Harris wanted to “make sure we are telling the world the story of progress that we have made in the US.”