Known as Petrocaribe, the program has helped over a dozen small countries in the region through a period of high oil prices by offering cheap credit for fuel from the oil-exporting OPEC member.

Although oil prices have fallen since last year, many of the participating countries have been hard hit by the global recession and are still dependent on Petrocaribe for their fuel needs.

Venezuela, which has suffered from the drop in oil income this year, now wants beneficiaries to pay upfront for a fixed percentage of the oil they receive. Under the current agreement, the up front payment varies with prices.

In a statement, Petrocaribe said the proposed changes would improve terms for the beneficiaries, but did not give details.

However, Dominican Republic and Jamaica have said in recent days that the proposal would seriously affect their budgets. Jamaica said Venezuela was asking for 80 percent of the value of the oil upfront.

The program has won Chavez many friends in the region, with several countries joining his ALBA trade agreement of mostly socialist countries.

Other Petrocaribe members include Antigua and Barbuda, the Bahamas, Belize, Dominica, Grenada, Guatemala, Guyana, Haiti, Honduras Nicaragua, Saint Kitts and Nevis, St Vincent and The Grenadines, Santa Lucia and Suriname.