The controversial 100 billion U.S. dollars a year Green Climate Fund came under renewed scrutiny at the United Nations climate talks in Durban, South Africa, on Thursday.

Business Day newspaper in Johannesburg reported that the International Federation of Liberal Youth said the amount pledged by industrialized nations is not enough.

The fund is intended to be able to disburse 100 billion U.S. dollars a year to developing nations by 2020.

However, the U.S., Saudi Arabia and some Latin American states want to reopen negotiations on the fund, including its governance structures.

Other nations reportedly believe the design of the fund should be signed off and it should start distributing as a work-in- progress.

Kyle Gracey, International Federation of Liberal Youth coordinator, told a media briefing in Durban that "We are very disappointed ...we need that fund and we need it yesterday, not today; and it must have money in it."

The Business Day reported that many developed nations are balking at putting money into the fund.

These nations point to the global financial downturn as a reason they can no longer afford to pay up.

Ousman Jarju, chairman of the Least-Developed Countries (LDC) grouping, said not even the 30 billion U.S. dollars "fast-start" finance fund, agreed to at the United Nations climate talks in 2010, is properly paid up.

He said there is only around 460 million U.S. dollars in the fast-start fund.

Jarju added that the 100 billion U.S. dollars is not enough to help developing countries properly deal with climate change.

He said the LDC group calculates that between 500 and 600 billion U.S. dollars will be needed annually from 2020.