WASHINGTON – The Obama administration appeared increasingly confident Wednesday that Edward Snowden's next plane trip will be a return flight to the United States, as U.S. diplomats stepped up pressure on other countries to deny political asylum to the fugitive former National Security Agency contractor.

State Department officials said they had urged other governments not to assist Snowden, who faces espionage charges for leaking highly classified documents about U.S. intelligence surveillance systems around the globe, spurring an international debate over the reach of U.S. spying.

"Officials have been in touch with a broad range of countries," State Department spokeswoman Jennifer Psaki said Wednesday. "We've been crystal-clear on what we want to happen."

Snowden has asked 21 countries for asylum to avoid U.S. prosecution, but none has offered him permanent refuge.

At the Justice Department, a senior official said the FBI and federal prosecutors were banking on Russian officials to break the stalemate and force Snowden to leave the international transit zone at Moscow's Sheremetyevo airport, where he apparently has holed up for the last 10 days. "There are laws for how long someone can stay there," the official said.

But a Russian Foreign Ministry official in Moscow said the law was not nearly so clear. "The fact that some countries are reluctant in offering or granting him asylum has nothing to do with terms of his stay at the Sheremetyevo transit zone," he said.

MCT