WASHINGTON — Striving to get Edward Snowden back to America, U.S., Attorney General Eric Holder has assured the Russian government the U.S. has no plans to seek the death penalty for the former National Security Agency systems analyst.

In a letter dated Tuesday, the attorney general said the criminal charges Snowden now faces in this country do not carry the death penalty and the U.S. will not seek his execution even if he is charged with additional serious crimes.

Holder’s letter followed reports that Snowden, who leaked details of top secret U.S. surveillance programs, has filed papers seeking temporary asylum in Russia on grounds that if he were returned to the U.S. he would be tortured and would face the death penalty.

Snowden has been charged with three offenses, including espionage, and could face up to 30 years in prison if convicted.

When Snowden arrived at Moscow’s international airport a month ago, he was believed to be planning to transfer to a flight to Cuba and then to Venezuela to seek asylum. But the U.S. canceled his passport.

Bruce Fein, a lawyer representing Edward Snowden’s father, criticized Holder.

“Today the attorney general stated — apparently thinking he was being conciliatory — that if Edward Snowden were returned to the United States we wouldn’t kill him or torture him. Those are concessions only in the mind of someone who’s very biased,” said Fein.

He said an impartial prosecutor would have said that Snowden is entitled to a presumption of innocence and that he would guarantee a fair trial.

The attorney general said that if Snowden returned to the U.S. he would promptly be brought before a civilian court and would receive “all the protections that United States law provides.”

A spokesman for President Vladimir Putin said Russia has not budged from its refusal to extradite Snowden. Dmitry Peskov told Russian news agencies that “Russia has never extradited anyone and never will.”