(CNN) -- Rumors that U.S. intelligence leaker Edward Snowden hitched a ride on Bolivia's presidential jet have sparked a global diplomatic feud that's roiled leaders throughout South America.

The drama started Tuesday after Portuguese authorities wouldn't let Bolivian President Evo Morales' plane land in Lisbon for refueling while on his way back from a conference in 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.

With no clear path home available, the flight's crew made an emergency landing in Austria.

"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, and subsequently took off for Fortaleza, Brazil, where it landed and refueled again Wednesday evening, Bolivia TV reported.

The presidential plane was scheduled to return to Bolivia on Wednesday night. The state broadcaster showed crowds of supporters brandishing Bolivian flags and awaiting Morales' return.

At the El Alto International Airport outside La Paz, the state broadcaster showed crowds waved signs saying, "Sovereign Bolivia, colony no more" and, "You are not alone. The people of the world are with you."

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The plane spent more than 10 hours in Vienna, where Austrian officials confirmed that Snowden was not aboard after Morales allowed an Austrian airport police officer onto his plane for a "voluntary check," Interior Ministry spokesman Karl-Heinz Grundboeck said.

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

France denied that it refused to allow the plane to enter its airspace.

French Foreign Minister Laurent Fabius called his Bolivian counterpart to express regrets about a delay in the confirmation to authorize the plane to fly over its territory, the French Foreign Ministry said in a statement.

The authorization was granted as soon as French authorities were informed that the plane was the Bolivian president's aircraft, the ministry said.

France "never intended to deny president Morales's plane access to (its) airspace," and the Bolivian leader is welcome in France, Fabius said.

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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."

Despite several attempts by CNN to get a response, Obama administration officials have declined to comment on Bolivia's allegations that the United States pressured European countries to deny landing rights to the Bolivian president's plane, referring all questions to the European countries in question.

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.

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 stern rebuke from Brazilian President Dilma Rousseff, who said the incident was "life-threatening" for the Bolivian leader.

"The Brazilian government expresses its outrage and condemnation of the embarrassment imposed on President Evo Morales by some European countries," she said in a statement Wednesday. "The pretext that led to this unacceptable behavior -- the supposed presence of Edward Snowden in the plane of the president -- was fictional and a serious disrespect to the law and to international practices and standards of civilized coexistence among nations."

The impact of the European countries' actions extends far beyond Bolivia's borders, she said.

"The embarrassment to President Morales reaches not only Bolivia, but all of Latin America. It compromises the dialogue between the two continents and possible negotiations between them," she said. "It also requires prompt and explanation by the countries involved in this provocation."

The Union of South American Nations released a statement Wednesday saying the body "rejects categorically the dangerous act" of denying Morales' plane access. The leaders of the UNASUR countries are scheduled to meet on Thursday meeting in Cochabamba, Bolivia, to discuss the matter.

By Wednesday evening, the presidents of Argentina, Venezuela, Peru, Suriname, Ecuador and Bolivia had confirmed their plans to attend, said Ecuadorian Foreign Minister Ricardo Patino, who called the situation "very serious."

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.

"This is not only a humiliation to a sister nation," she said during a military event Wednesday, "but to the whole South American continent."

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.

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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.

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.

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