Rumors that U.S. intelligence leaker Edward Snowden hitched a ride on the Bolivian presidential jet forced the plane's temporary grounding in Austria and sparked outrage in several South American countries.

The drama grew late Tuesday when Portuguese authorities wouldn't let Bolivian President Evo Morales' plane land in Lisbon for refueling while on his way back from Russia, Bolivian Defense Minister Ruben Saavedra told CNN en Español.

France, Spain and Italy also wouldn't let the plane enter their airspace, Bolivian officials said. Such restrictions would cut off any direct path from Austria to Bolivia.

"We are told that there were some unfounded suspicions that Mr. Snowden was on the plane," Bolivian Foreign Minister David Choquehuanca said.

"We do not know who has invented this lie. Someone who wants to harm our country. This information that has been circulated is malicious information to harm this country."

Late Wednesday morning, Spain agreed to let Morales' plane stop in the Canary Islands on its way home, the Spanish Foreign Ministry said. The plane landed there as planned Wednesday afternoon, and subsequently took off for Fortaleza, Brazil, the final stop before returning to Bolivia.

Morales' plane took off from Vienna shortly afterward, the Austrian Interior Ministry said. But by that time, he had spent more than 10 hours in Vienna.

Austrian officials made a voluntary check of Morales' plane and confirmed that Snowden was not on board, Interior Ministry spokesman Karl-Heinz Grundboeck said.

As Morales resumed his journey, differing accounts emerged of what happened.

French Minister for European Affairs Thierry Repentin told reporters Wednesday in Paris that France had authorized Morales' plane to enter its airspace.

France does not wish to stir up any controversy in the media on this subject, he said.

While in Vienna, Morales met with Austrian President Heinz Fischer and said he was "surprised by his solidarity."

"His presence means a lot. Neither Bolivia nor its president commits erroneous crimes," Morales told Bolivian state-run TV. "I am respectful of international laws, and the presence of the president strengthens me."

Outrage in Latin America

Bolivian Vice President Alvaro Garcia Linera described Morales as a "hostage of imperialism."

"The president has been kidnapped by imperialism, and he is being held in Europe," he said in a televised address late Tuesday night. The vice president called for workers worldwide to protest "this act of imperial arrogance."

He said Bolivia would complain about the incident to the United Nations.

The situation drew a swift rebuke from Ecuador's foreign minister, Ricardo Patino, who told reporters he planned to call a regional meeting of the Union of South American Nations, known as UNASUR, to discuss it.

UNASUR released a statement Wednesday saying the body "rejects categorically the dangerous act" of denying Morales' plane access. The leaders of the UNASUR countries decided on a Thursday meeting in Cochabamba, Bolivia.

Cuba's Foreign Ministry also condemned the incident.

"This constitutes an unacceptable, unfounded and arbitrary act which offends all of Latin America and the Caribbean," the ministry said in a statement.

Argentina's President Cristina Fernandez de Kirchner described Morales' treatment in Europe as "humiliating," the state-run news agency Telam reported.

So where is Snowden?

The situation is the latest twist in what has become a global guessing game over Snowden's next steps.

Snowden has admitted leaking classified documents about U.S. surveillance programs and faces espionage charges in the United States. He has applied for asylum in 21 countries, including Bolivia.

Morales, a left-leaning president who has long criticized the United States, had been attending a conference of gas-exporting countries in Russia, where he told the Russia Today news network that he would be willing to consider asylum for Snowden.

But Bolivian officials stressed that accusations that an official aircraft would harbor Snowden were baseless.

"We cannot lie to the international community by carrying ghost passengers," Choquehuanca said.

Garcia Linera said that since the plane's landing in Austria, some European officials have said they would let the plane fly over their airspace only if investigators are allowed to search it -- a condition that the vice president called unacceptable.

"We are not going to accept blackmail or any type of conditions," he said.

European concerns

WikiLeaks founder Julian Assange urged Europe on Wednesday to demonstrate its willingness to defend freedom of information, whatever the fear of political pressure from its "best ally," the United States.

His comments came in a piece co-written with the secretary general of Reporters without Borders, Christophe Deloire, for French newspaper Le Monde.

European Union states should accord Snowden their warmest welcome, their article said. If he is abandoned in the international zone of Moscow's Sheremetyevo International Airport, it will mean European countries are "abandoning their principles and part of the reason for the EU," it said.

In recent days, a number of European nations have voiced concern about reports -- based on documents apparently provided by Snowden -- that the United States has been conducting surveillance on its European allies.

France believes it would be wise to delay U.S.-EU trade talks for two weeks in light of the allegations, French government spokeswoman Najat Vallaud-Belkacem said Wednesday.

She was echoing remarks made by President Francois Hollande this week after the claims first appeared in German and British media.

Germany's Economy Minister Philipp Roesler has said the reports of spying do influence the planned talks, said his spokesman, Adrian Toschev.

But the spokesman declined to back the French call for a delay to the talks, which are scheduled to begin Monday.

Bolivian minister: U.S. behind Snowden rumor

Bolivian authorities are investigating the source of the rumors about Snowden. Saavedra, the Bolivian defense minister, told CNN en Español that he believed the U.S. was behind them.

"This is a lie, a falsehood," he said. "It was generated by the U.S. government."

Bolivia's air travel rights were violated, he said.

"It is an outrage. It is an abuse. It is a violation of the conventions and agreements of international air transportation," he said.

The original flight plan had a refueling stop scheduled in Lisbon, said Saavedra, who is traveling with Morales. Once Portuguese authorities told them they couldn't land there for "technical reasons," the crew changed course for the Canary Islands, the defense minister said.

Right before the plane was about to fly over the French border, authorities there said they couldn't enter the country's airspace, again citing "technical issues," according to Saavedra.

"The crew informed us of this situation ... and out of caution they suggested we turn back and land at the airport in Vienna, which we did," Saavedra said.

Bolivia's foreign minister told reporters that the move had put the president's life at risk.

"Portugal owes us an explanation. France owes us an explanation," Choquehuanca said.

A history of tense relations

It isn't the first time Bolivian authorities have accused U.S. officials of trying to meddle with their presidential plane.

In 2011, Morales said he was worried that U.S. authorities would plant something on his presidential plane to link him with drug trafficking when he attended a United Nations General Assembly meeting.

"I think they have to be preparing something," he told a convention of female farm workers. "So much that I'm afraid to go with our airplane to the United States."

Bolivia and the United States have had diminished relations since September 2008, when each country expelled the other's ambassador.

Morales, a strong proponent of the cultivation of coca plants -- the source of cocaine -- expelled the U.S. Drug Enforcement Administration a month later. He also delivered a strong verbal criticism of the U.S. government at the United Nations General Assembly that year.

In May, Morales said he was expelling the U.S. Agency for International Development from his country for allegedly meddling and conspiring against the government.

The U.S. State Department denied the accusation, called the decision regrettable and said the ones who will be hurt by the expulsion will be ordinary Bolivians.

CNN's Claudia Dominguez, Antonia Mortensen, Richard Allen Greene, Stephanie Halasz, Stephanie Ott, Al Goodman, Ivana Kottasova, Claudia Rebaza, Laura Richardson, Patrick Oppmann and Rafael Romo contributed to this report.