– Attorney General Eric Holder took a strong stand Thursday against granting amnesty to Edward Snowden but did not rule out the possibility of plea negotiations.

"He broke the law," Holder said in an interview with MSNBC's Ari Melber about Snowden, the former National Security Agency contractor who has been charged with espionage for releasing intelligence-gathering secrets.

"In fact he caused harm to our national security. and I think he has to be held accountable for his actions," Holder said. "People have really gotten hung up over whether he is a whistleblower or something else. From my perspective, he is a defendant."

MSNBC said Holder rejected any notion of amnesty for Snowden. But Holder did say that the United States "would engage in conversation" about a resolution with Snowden if he accepted responsibility for leaking secrets, the network reported.

In an appearance later Thursday in Virginia, Holder made it clear that any talks would have to be based on Snowden's returning to the United States from Russia, where he is now living, and pleading guilty to federal charges.

"If Mr. Snowden wanted to come back to the United States and enter a plea, we would engage with his lawyers," Holder said. "We would do the same with any defendant who wanted to enter a plea of guilty."

Fielding mostly friendly questions posed to him via Twitter, Snowden on Thursday addressed the issue in a Web chat that he conducted from Moscow.

"Returning to the U.S., I think, is the best resolution for the government, the public and myself," he said. "But it's unfortunately not possible in the face of current whistleblower protection laws, which through a failure in law did not cover national security contractors like myself."