A federal magistrate judge has agreed that an anti-Castro Cuban militant should be able to leave a federal immigration jail while waiting to be deported.

Luis Posada Carriles’s lawyer, Felipe D.J. Millan, said the ruling will now go to a federal district judge. If the ruling is upheld, he anticipates Mr. Posada could be set free in 30 days.

The 78-year-old Cuba native and naturalized Venezuelan citizen is wanted in Venezuela for plotting the 1976 bombing of a Cuban jetliner.

Eric Wingerter, a Venezuelan government spokesman in Washington, said the ruling “is exactly the wrong message to be sending” in time of an increased focused on fighting terrorism.

“We’re talking about a guy who blew up an airplane that was holding the most innocent people,” Mr. Wingerter said. “If that is not the definition of a terrorist, I don’t know what is.”

“If we are serious about fighting terrorism then we need to prosecute all terrorists, not just those opposed to U.S. foreign policy.”

Lawyers for the Venezuelan government are continuing efforts to have Mr. Posada sent back to face trial.