Compose the next sentence for this paragraph.

The United States hasn't abandoned Robert Levinson, the retired FBI agent described by his wife as the "longest-held American hostage," Secretary of State John Kerry said Sunday. "There hasn't been progress in the sense that we don't have him back. But to suggest that we've abandoned him or anybody ... is simply incorrect and not helpful," Kerry told ABC's "This Week." "The fact is that I have personally raised the issue, not only at the highest level that I have been involved with, but also through other intermediaries." Levinson disappeared in Iran in March 2007 during a business trip, purportedly undertaken as a private investigator looking into cigarette smuggling. However, The Associated Press and the Washington Post reported Thursday that contrary to what the State Department and Levinson's family have said for years, Levinson actually was working for the CIA in Iran. And a source involved in the matter told CNN there's proof that Levinson worked for the CIA undercover, and under contract, while also working as a private investigator.

This year, a source with knowledge of the investigation told CNN, "We have every reason to believe that he's alive and that the
Iran control his fate."