The US Justice Department is exploring a legal pursuit of Julian Assange, said Vice President Joe Biden, who described the WikiLeaks founder as a dangerous "hi-tech terrorist."
"We're looking at that right now," Biden told NBC's Sunday talk show "Meet the Press," but the vice president stopped short of elaborating on just how the administration could act against the head of the organisation whose release of thousands of classified US diplomatic cables has enraged Washington.
"I'm not going to comment on that process." When asked whether he thought Assange was a high-tech terrorist or a whistleblower akin to those who released the Pentagon Papers - a series of top-secret documents revealing US military policy in Vietnam - Biden was clear: "I would argue that it's closer to being high-tech terrorist."
Legal pressure has been building steadily on WikiLeaks and Assange, who is in England fighting extradition to Sweden, where he faces sexual assault allegations.
Assange said Friday it looked "increasingly likely" that the United States would try to extradite him on charges related to the leaked cables.
A report by congressional researchers found the Espionage Act and other US laws could be used to prosecute the 39-year-old Australian hacker, but there is no known precedent for prosecuting publishers in such a case.
A group of US senators early this month introduced a bill to make it easier to target the self-described whistleblowing website by making it illegal to publish names of informants serving the US military and intelligence community.
Media reports suggested that US prosecutors are trying to build a case against Assange on the grounds that he encouraged US Army Private Bradley Manning, currently in US custody, to steal American cables from a government computer and pass them to WikiLeaks.
Assange has denied knowing Manning. Biden appeared to leave the door open for charges against Assange.
"If he conspired to get these classified documents with a member of the US military, that's fundamentally different than if somebody drops (documents) on your lap here, (saying) 'You're a press person, here is classified material.'"
In a legal case, the United States would seek to show Assange's responsibility for damage to national security, but legal experts have said the path to prosecution is strewn with legal complications, including constitutional free speech protections.
Biden insisted WikiLeaks "has done damage" through its documents dump.
"Look, this guy (Assange) has done things that have damaged and put in jeopardy the lives and occupations of people in other parts of the world," Biden said.
In particular, he acknowledged that among world leaders concerned over the leaks, "there is a desire now to meet with me alone rather than have staff in the room."