South American foreign ministers met with Venezuelan officials in Caracas Friday in hopes of encouraging dialogue between opposition leaders and the socialist administration to head off a political crisis.

Leaders of Caribbean nations were also gathering for a meeting of Petrocaribe, a decade-old trade program created by the late President Hugo Chavez that requires member countries to pay only a small portion of the up-front costs for oil, allowing them to finance the rest under long-term debt agreements.

With the price of crude crashing, Venezuela is struggling economically and is looking for ways to wring cash out of the alliance's debts.

The foreign ministers from the 12-nation UNASUR group were also expected to meet with Venezuela's opposition coalition.

The group last visited in May, trying to calm conflicts between the administration and protesters who staged weeks of violent street demonstrations. Those talks broke down, and the country remains as polarized as ever.

The opposition has expressed skepticism about the visit, while President Nicolas Maduro said he welcomed it. Meanwhile, 33 local and international non-governmental groups signed on to a letter to UNASUR urging it to help ensure respect for human rights in Venezuela.

Among other things, the letter calls for a revision of a policy that allows for the deadly use of force to control protests.

Last month, a policeman killed a 14-year-old boy during an anti-government protest, raising tensions that had already been running high amid a crackdown on the opposition and crippling economic problems.