The United States and South Africa have reportedly reached a deal to allow the release of $1.5 billion in frozen Libyan assets, to be used by the country's opposition-run council for urgent humanitarian aid.

Those assets had been blocked under U.N. sanctions against the government of Moammar Gadhafi. But U.S. officials said Thursday the money is urgently needed to provide fuel, food, clean water and other essential services to the Libyan population.

Diplomats at the United Nations say the move to release the funds was authorized after negotiations within the U.N. Security Council's Libya sanctions committee.

South Africa on Wednesday had expressed hesitation about releasing the funds, concerned they may end up in the wrong hands.

To win South African approval, Washington agreed to modify the wording of the deal. Instead of asking that the funds be released specifically to the opposition's Transitional National Council, the agreement says they will be designated for what's being called the “relevant authorities” in Libya.

U.S. officials said the money should reach the TNC in a matter of days.

In Washington, meanwhile, U.S. Secretary of State Hillary Clinton said that although situation in Libya remains fluid, it is clear that the Gadhafi era is coming to an end, opening the way for a new era of liberty, justice, and peace.

In a statement issued Thursday, Clinton said the United States joins the Libyan people in celebrating what she called “the courageous individuals” who have stood up to a tyrant and defended their homes and communities against Gadhafi's violence.

The top U.S. diplomat said the coming days will be critical. She said the Libyan people made this revolution and they will lead the way forward, adding they deserve “our help.”

Earlier Thursday, the Libya Contact Group meeting in Istanbul urged the U.N. to unlock frozen Libyan assets.

And the Arab League has accepted the Transitional National Council as the legitimate representative of the Libyan state.