Washington (CNN) -- President Barack Obama is calling for the immediate release of three American hikers seized by Iranian forces along the Iraqi border who will have been in custody for exactly a year on Saturday. "Their unjust detention has nothing to do with the issues that continue to divide the United States and the international community from the Iranian government," Obama said in a statement Friday. "This is a humanitarian imperative, as these three young people are innocent of any crime." The three Americans -- Sarah Shourd, Shane Bauer, and Josh Fattal -- were detained after they allegedly strayed across an unmarked border while hiking in Iraq's Kurdistan region. The Nation magazine reported last month that two witnesses have said they saw members of Iran's national police force cross into Iraq to apprehend the three. Tehran has claimed the three hikers are spies. Iran's intelligence minister has hinted the country may consider releasing them in exchange for the release of Iranian prisoners, according to state media. "I want to be perfectly clear: Sarah, Shane and Josh have never worked for the United States government," Obama said. "They are simply open-minded and adventurous young people who represent the best of America, and of the human spirit. They are teachers, artists, and advocates for social and environmental justice. They have never had any quarrel with the government of Iran, and have great respect for the Iranian people." The president said he spoke with the hikers' mothers this week and noted that the Iranian government allowed the women to visit their children earlier this year. But "I cannot imagine how painful it was for these three courageous women to return home without their children. I told these three mothers that Sarah, Shane and Josh are in my thoughts and prayers, and that the U.S. government would continue to do all that it could to secure their release." Meanwhile, the mothers continue to grow increasingly angry and exasperated as they press the Iranian government to free their children. "This is unbelievable to us at this point," Nora Shourd told CNN's American Morning earlier Friday. "I mean, it is outrageous that they are still there." Shourd, the mother of hiker Sarah Shourd, said at first they thought the ordeal would be "over fairly quickly." She said it has gone on "long enough." Obama also recently spoke with the wife of Robert Levinson, a former FBI agent who went missing in Iran over three years ago. "We continue to have no information about his welfare, and reiterate our call for the government of Iran to provide any information that it has about his whereabouts," the president said. "It is time to facilitate Robert Levinson's return to the family and friends who have suffered so greatly in his absence."
Three American hikers have been in Iranian custody for a year on Saturday .
Obama says the hikers are "innocent of any crime" and calls for their release .
Iran has accused the three of espionage .
Washington (CNN) -- President Barack Obama is calling for the immediate release of three American hikers seized by Iranian forces along the Iraqi border who will have been in custody for exactly a year on Saturday. "Their unjust detention has nothing to do with the issues that continue to divide the United States and the international community from the Iranian government," Obama said in a statement Friday. "This is a humanitarian imperative, as these three young people are innocent of any crime." The three Americans -- Sarah Shourd, Shane Bauer, and Josh Fattal -- were detained after they allegedly strayed across an unmarked border while hiking in Iraq's Kurdistan region. The Nation magazine reported last month that two witnesses have said they saw members of Iran's national police force cross into Iraq to apprehend the three. Tehran has claimed the three hikers are spies. Iran's intelligence minister has hinted the country may consider releasing them in exchange for the release of Iranian prisoners, according to state media. "I want to be perfectly clear: Sarah, Shane and Josh have never worked for the United States government," Obama said. "They are simply open-minded and adventurous young people who represent the best of America, and of the human spirit. They are teachers, artists, and advocates for social and environmental justice. They have never had any quarrel with the government of Iran, and have great respect for the Iranian people." The president said he spoke with the hikers' mothers this week and noted that the Iranian government allowed the women to visit their children earlier this year. But "I cannot imagine how painful it was for these three courageous women to return home without their children. I told these three mothers that Sarah, Shane and Josh are in my thoughts and prayers, and that the U.S. government would continue to do all that it could to secure their release." Meanwhile, the mothers continue to grow increasingly angry and exasperated as they press the Iranian government to free their children. "This is unbelievable to us at this point," Nora Shourd told CNN's American Morning earlier Friday. "I mean, it is outrageous that they are still there." Shourd, the mother of hiker Sarah Shourd, said at first they thought the ordeal would be "over fairly quickly." She said it has gone on "long enough." Obama also recently spoke with the wife of Robert Levinson, a former FBI agent who went missing in Iran over three years ago. "We continue to have no information about his welfare, and reiterate our call for the government of Iran to provide any information that it has about his whereabouts," the president said. "It is time to facilitate Robert Levinson's return to the family and friends who have suffered so greatly in his absence."
American hikers seized by Iranian forces along the Iraqi border who will have been in custody for exactly a year on Saturday. "Their unjust three young people are innocent of any crime." three. Tehran has claimed the three hikers are