The United States has been waging a multi-country diplomatic effort to ensure Edward Snowden is returned to American authorities to face espionage charges, Secretary of State John Kerry asserted in an interview with CNN Monday.

Snowden, who admittedly leaked top secret information about government surveillance programs, left Hong Kong on Sunday and has thus far avoided U.S. extradition efforts. The United States has revoked his passport and encouraged countries to deny him asylum.

Asked how a man wanted on espionage charges was able to travel freely from Hong Kong to Russia, Kerry defended the U.S. government's role in trying to apprehend Snowden. He noted Snowden's passport was revoked as soon as the government's complaint against him was unsealed last week – before Snowden departed Hong Kong.

"We don't know what authorities allowed him to leave under those circumstances," Kerry told CNN foreign affairs reporter Elise Labott. "We obviously have to find out from the Chinese what happened. We hope that the Russians will recognize the request of the United States."



International cooperation from Hong Kong, Russia, and other countries is essential in upholding "the rule of law," Kerry added.

On Sunday, Hong Kong authorities said the United States' extradition request did not meet its requirements to return Snowden. However, there's been speculation the semiautonomous Chinese city allowed Snowden to leave as retaliation for details about U.S. spying in China that Snowden revealed earlier this month.

The secretary of state would not concede that China may have allowed Snowden to leave Hong Kong for those reasons, saying he's seen nothing to indicate Beijing intervened in the decision.

"What we have here is a situation that has nothing to do with hacking. Nothing to do with illegality. Nothing to do with stealing. Everything to do with national security. In fact, their national security is at risk and at stake in the very same way," Kerry said.

Those risks could include the deaths of Americans at the hands of terrorists who now know more about U.S. surveillance programs, Kerry claimed.

Speaking about Snowden, Kerry said he sees "an individual who threatened his country and put Americans at risk though the acts that he took."

"People may die as a consequence to what this man did," he continued. "It is possible that the United States would be attacked because terrorists may now know how to protect themselves in some way or another that they didn't know before. This is a very dangerous act."