The Obama administration sent the first $500 million to the United Nations' Green Climate Fund this week, thumbing its nose at Republican opponents who say taxpayers shouldn't be on the hook for the money.

Critics of the U.S. participating in the fund came out against the president's actions Tuesday.

"President Obama continues to prioritize his political interests over the interests of the American people," said Tom Pyle, president of the conservative American Energy Alliance. "The administration intends to funnel hundreds of millions of taxpayer dollars into the U.N.'s climate slush fund while pursuing a domestic agenda that will raise energy costs and leave all Americans poorer."

The payment is part of the climate deal President Obama helped pull together in Paris in December. The $500 million is part of a $3 billion commitment to the fund by the U.S. to help poorer countries cope with the effects of climate change.

The Green Climate Fund is slated to be funded with $100 billion a year beginning in 2020, but that amount is expected to ratchet up.

Pyle said by "diverting this money with little to no transparency or clear authorization," Obama is ignoring more pressing demands such as those grappling with a spill the Environmental Protection Agency caused in Colorado last year. The spill released 3 million gallons of toxic sludge into the waterways of three states and is a key sticking point between the Congress and the administration.

The payment went out ahead of Canadian Prime Minister Justin Trudeau meeting with Obama on Wednesday for an official state visit. The two are expected to announce a number of climate change initiatives in preparation for a signing ceremony next month for the Paris deal in New York.

"With no more campaigns to run, the president is no longer accountable to the American people," Pyle added. "That makes it even more important that Congress holds him accountable. After all, they hold the power of the purse. Now they must show they can use it."