The White House and Secretary of State John Kerry marked the sixth anniversary of the date retired FBI agent Robert Levinson went missing during a business trip in Iran, calling on the Iranian government to help.

"Finding him remains a high priority for the United States, and we will continue to do all that we can to bring him home safely to his friends and family, so they may begin to heal after so many years of extraordinary grief and uncertainty," Press Secretary Jay Carney said. He noted that the Iranian government previously offered help in finding Levinson "and we look forward to receiving this assistance, even as we disagree on other key issues."

The FBI has announced a $1 million reward for information leading to Levinson's safe return. Kerry, who met with Friday with Levinson's wife and son, noted that the Florida man is a husband and father of seven and has "missed birthdays, anniversaries, weddings, and other important milestones since his disappearance six years ago from Iran's Kish Island."

He's also the grandfather of two, Kerry noted, "the second of which was born in his absence."