"Latin America demands an explanation," tweeted Ecuadorean leader Rafael Correa. "If what happened to Evo does not merit a Unasur summit, I don't know what does."
Dilma Rousseff, president of regional economic powerhouse Brazil, issued a statement repudiating the European countries that denied Morales access to their airspace based on what she called the "fanciful" notion that Snowden might be on board.
The Chilean Foreign Ministry issued a statement saying it "lamented" what happened to Morales and that more clarity was needed on the facts.
A spokesman at France's Foreign Ministry blamed the flap on "an administrative mishap," saying France never intended to ban Morales from its airspace and that there were delays in getting confirmation that the plane had fly-over permits.
International agreements allow civilian airplanes to overfly countries without obtaining permission ahead of every flight. But state aircraft including Air Force One, the plane that carries the U.S. president, must obtain clearance before they cross into foreign territory.
Government aircraft, whether carrying diplomats or missiles, always require approval before they can enter foreign airspace, legal experts said.
"Every state on the basis of state sovereignty has the right to deny overflight to state aircraft," said John Mulligan, a research fellow at the International Aviation Law Institute at DePaul University in Chicago.