A U.S. senator from New Jersey is urging the Portuguese government to return an American fugitive who escaped from a state prison in 1970 and spent more than 40 years on the lam before being captured in September in Portugal.

Sen. Frank Lautenberg said Monday he has sent a letter to Portugal's prime minister asking him to send George Wright back to the U.S. to serve the rest of his 15- to 30-year sentence for the 1962 killing of a gas station attendant during a robbery in New Jersey.

The Portuguese government has refused to extradite Wright. It cites the fact he's now a citizen of that country and says the statute of limitations on the New Jersey murder has expired.

The U.S. government is appealing the decision.