WASHINGTON — The US Senate unanimously approved a resolution urging Iran to fulfill its pledge to help find Robert Levinson, a Jewish American who went missing in Iran in 2007.Five Americans were released last month in a prisoner exchange with Iran timed to mark the launch of the implementation of the sanctions relief for nuclear rollback deal between Iran and six major powers. The Iranians said they would assist in tracking down Levinson; the Obama administration believes he is no longer in Iran.The non-binding resolution approved Thursday, sponsored by Sens. Bill Nelson and Marco Rubio, respectively a Democrat and a Republican from Levinson’s home state of Florida, “notes the pledges by current Iranian officials to provide their government’s assistance in the Robert Levinson case” and “urges Iran, as a humanitarian gesture, to intensify its cooperation in the Robert Levinson case and to share the results of its investigation into his disappearance with the US government.”Levinson, 68, of Coral Springs, Florida, a private detective and a former FBI agent, has been missing since disappearing from Iran’s Kish Island during what has since been revealed as a rogue CIA operation.Rep. Ted Deutch, D-Fla., who represents Levinson’s southern Florida district, is advancing a similar motion in the US House of Representatives. It was approved this week by the House’s Middle East subcommittee.