The United States again pressed Tehran over the weekend for any information they could provide on a former FBI agent missing in Iran.
"We have no evidence to suggest that he has actually left," McCormack said. "So we've gone back to the Iranian government, restated that."
U.S. contact with Tehran is handled through the Swiss as Washington broke diplomatic ties with Tehran after Iranian militant students stormed its embassy in Tehran in 1979 and held its occupants hostage for 444 days.
Last week, the Iranian government said it had no "record" of the former FBI agent, who was last seen on the Iranian island of Kish in early March.
Levinson, 59, of Coral Springs, Fla., was reported missing March 11. He retired from the FBI in 1998 and was on private business in Kish before he disappeared.
The FBI says Levinson never dealt with intelligence or counterterrorism while an agent.
In addition, the State Department has asked other European nations for help on the Levinson matter.
"We've also asked a couple of European governments last week to go in and essentially knock on doors and see if they can determine any information about his whereabouts," McCormack said.
On April 16, Levinson's wife issued a plea from Florida for information on the whereabouts of her husband, who was believed to be on the Persian Gulf island, known for its beaches, sea turtles and relatively liberal atmosphere, doing research for an independent filmmaker.
U.S. citizens are not barred from traveling to Iran but must obtain a visa, although no Iranian visa is required to visit Kish island.
FOX News' Catherine Herridge and the Associated Press contributed to this report.