BOGOTA -- The hemisphere is throwing a party, but not everyone’s invited.

On Friday, the leaders of 33 Latin American and Caribbean countries are gathering in Venezuela to forge a new organization that will include every nation in the region — except the United States and Canada.

Some are hoping the Community of Latin American and Caribbean States, or CELAC, will blunt U.S. influence in the region and replace the Organization of American States, the only group that’s opened to all countries in the hemisphere. The OAS, which promotes democracy and development in the region, has been accused by some nations of being a U.S. mouthpiece.

The new body comes to life as Latin America is flexing its muscles on the world stage and the region is expected to see economic growth of almost 5 percent this year on the back of surging commodity prices. It also comes amid hand-wringing over waning U.S. influence in the region.

Venezuelan President Hugo Chávez — the event’s host and promoter — has called the CELAC a “historic” organization that will bring the region closer together as it shakes off the United States’ imperialist pretensions. The event culminates Saturday with the signing of the Caracas Declaration that formally launches the bloc. Chile will head the organization in its first year, followed by Cuba in 2013.

The administration is not worried that the organization will someday replace the OAS, said Dan Restrepo, President Barack Obama’s senior advisor on Latin America.

“The notion that you can create an organization simply to be anti-American is not viable over a sustained period of time,’’ Restrepo told The Miami Herald on Thursday.

Despite the flailing U.S. economy, it’s still the hemisphere’s powerhouse and the principal destination for most Latin American exports, including Venezuela’s. And unless the CELAC receives solid financial backing, such as the OAS receives from the United States, it’s unlikely to flourish, said Dennis Jett, the former U.S. ambassador to Peru and a professor at Penn State University.

“This organization will probably last as long as Chávez is willing to underwrite it,” Jett said, “and I’m not sure how much longer he can do that.”

While the CELAC is a regional effort, it’s Chávez’s baby. Originally scheduled for July, the formation of the CELAC was delayed as Chávez traveled to Cuba to undergo treatment for an undisclosed form of cancer.

He says that he’s cured and has stepped up his public appearances, but that hasn’t stopped reports that his condition is far more serious than he lets on. In that sense, the CELAC marks Chávez’s return to the world stage as he eyes a tight presidential race in October.

While the full impact of the organization won’t be known for years, some worry that it could become a tool for governments that have bristled under international criticism.

Ecuador President Rafael Correa is proposing the creation of a human rights venue within the CELAC that would supplant the OAS’s influential Inter-American Commission on Human Rights.

“It’s not possible that Latin American conflicts have to be dealt with in Washington, where the Inter-American Commission on Human Rights is, when even United States doesn’t recognize the commission,” he said in a statement. “Sooner rather than later [the CELAC] should replace the OAS, which has historically been distorted.”