Former U.S. intelligence contractor Edward Snowden, who is wanted by Washington on espionage charges, reportedly did not travel, as expected, on a flight from Moscow to Havana.
Reuters and Interfax report the Cuba-bound plane left without Snowden.
The U.S. government has asked Russia to expel Snowden to the United States, where he faces charges of leaking information about secret U.S. government surveillance programs. Russia said it had no reason to detain the former National Security Agency contractor.
Speaking during a visit to India, U.S. Secretary of State John Kerry warned Russia about helping Snowden evade U.S. justice.
"It would be very disappointing if he was willfully allowed aboard an airplane," Kerry said. "As a result, there would be, without any question, some effect and impact on the relationship, and consequences."
The Ecuadoran ambassador to Russia met with Snowden on June 23, fueling speculation that his ultimate destination may be Ecuador. Ecuadoran Foreign Minister Ricardo Patino said on June 24 that his government is considering Snowden's asylum request.
"Let us end the speculation," Patino said. "We will make the decision in time. We are analyzing it with a lot of responsibility and taking good care of it because it has to do with the freedom of expression, with the security of citizens around the world, and therefore we have to analyze it deeply."
U.S. Senator Chuck Schumer (Democrat-New York) criticized Russia's decision not to hand over Snowden to U.S. authorities during an appearance on the CNN program "State of the Union" on June 23.
"What is infuriating here is [Russian President Vladimir] Putin aiding and abetting Snowden's escape," Schumer said. "The bottom line is very simple: Allies are supposed to treat each other in decent ways. And Putin always seems almost eager to put a finger in the eye of the United States -- whether it is Syria, Iran, and now, of course, with Snowden. That's not how allies should treat one another and I think it will have serious consequences for the United States-Russia relationship."
Snowden arrived in Moscow on June 23 from Hong Kong where he had been in hiding since the leaked information was publicized earlier this month.
Hong Kong's government said a U.S. arrest warrant for Snowden failed to meet its judicial requirements.
Britain's "Guardian" newspaper and "The Washington Post" cited documents provided by Snowden to reveal a vast U.S. government effort to collect and monitor – through companies such as Google, Facebook, and other communications providers -- the phone and Internet data of millions of people in America and around the world.
U.S. President Barack Obama's administration has said the surveillance programs have congressional and judicial oversight and have helped to thwart as many as 50 terrorist plots, some of them aimed at targets in the United States.
Kerry also addressed that issue during the press conference in India.
"This is a dangerous and complicated world we all live in," he said, "and I believe that the program the United States has pursued is a very judicious balance of civil rights, civil liberties, but also of the right of people to live free from being killed by terrorists."
Last week, U.S. authorities charged Snowden with theft of government property, unauthorized communication of national defense information, and willful communication of classified intelligence information to an unauthorized person.
Each of the three charges carries a maximum 10-year prison penalty following a conviction.
With reporting by Reuters and ITAR-TASS