A Republican senator is accusing President Obama of spending money that could have been used on fighting the Zika virus on an international fund to fight the effects of climate change.

Sen. James Lankford, R-Okla., wrote in an op-ed published Tuesday that Obama knew in March that foreign countries and the United States would need funding to fight the Zika virus. However, instead of taking that money and putting it toward the growing health crisis, he sent a $500 million payment to the United Nation's Green Climate Fund.

The money Lankford wrote about comes from an $80 billion intenrational fund controlled by the State Department, Department of Health and Human Services and International Assistance Programs that is not legally obligated for any particular program.

"Congress refused to allocate funding for the U.N. Climate Change Fund last year, so the president used this account designated for international infectious diseases to pay for his priority," Lankford wrote in the Daily Signal, the news outlet of the conservative Heritage Foundation.

According to Lankford, Obama could have used money from the fund to send money to foreign countries to fight the Zika virus and prevent it from spreading to the United States without adding any debt to the United States' bottom line. However, he is instead encouraging legislative action that would add to the deficit.

Lankford argues the fund is meant solely to fight infectious diseases abroad, but the fund is set up for international aid. During deliberations over the Paris Agreement in Congress, the administration argued it is within its rights to spend the international aid fund how it sees fit.

The Green Climate Fund is one of the provisions in the Paris climate change accord, signed by the U.S. and 195 other countries in December. It would serve as a means to distribute money from rich countries to poorer countries to help them improve their infrastructure against climate change.

Congressional Republicans have moved to block the administration from allocating money to the climate fund. It is not one of the legally enforceable parts of the Paris Agreement and therefore does not need congressional approval.

The White House did not immediately respond to a request for comment on Lankford's comments.