WASHINGTON — Florida Sen. Bill Nelson is calling on Congress to press Iran into divulging more information about Robert Levinson, a retired FBI agent who went missing in 2007 from a Persian Gulf island.

The congressional resolution calls for Iranian investigators to meet with the FBI to discuss Levinson's case, as well as calling on the U.S. government and its allies ''to press Iran on this case, at every opportunity and at every level,'' Nelson said.

''No one should ever have to experience what they have been through,'' Nelson said of Levinson's wife, Christine, and his seven children. "It is no doubt the wish of everyone who knows the family that Mr. Levinson be reunited with his loved ones and it has been very difficult to get information out of the government of Iran.''

Levinson, who lives in Coral Springs, was last seen in March 2007 on Kish, a resort island in the Persian Gulf, where he was trying to uncover information on cigarette smuggling for a client of his security firm.

His signature appears in a resort log book, showing that he checked out. But his passport hasn't turned up.

Nelson noted that Christine Levinson last December traveled to Iran to get more information and that Iranian officials pledged more help, "but those promises have not been fulfilled.''

He noted that Iranian President Mahmoud Ahmadinejad said in a July interview with NBC that Iranian officials were willing to cooperate with the FBI on this case, but that "they have not.''

The resolution, he says, "calls upon Tehran to make this meeting happen as soon as possible to discuss the evidence the Iranians have uncovered about Mr. Levinson's disappearance.''

''Let me be blunt,'' Nelson said on the Senate floor. "We obviously have serious disagreements with Iran on its nuclear program and a whole range of other issues. . . . But I am calling on the government of Iran, out of human compassion and humanitarian assistance to a family to come forth and cooperate in trying to find . . . Bob Levinson.''

Nelson said he hopes to have Christine Levinson -- whom he called a ''a loving mother, an eloquent advocate and a tough fighter on behalf of her husband'' -- visit Washington in January to further press her case.

''We cannot forget Bob Levinson and his family,'' he said.