The United States on Tuesday said it had not been granted access to three hikers held in Iran for three months and feared they were being held under "deplorable conditions", dpa reported.
"It is outrageous that Iran refuses to abide by international standards, international agreements in terms of treatment of those who are in their care," State Department spokesman PJ Crowley told reporters.
Three US hikers were detained by Iran when they strayed across the border from Iraq's Kurdish region in July. They have been held in Tehran's notorious Evin prison.
"It's why we have demanded consular access repeatedly of the Iranian government, and unfortunately we have not had, you know, consular access through our protecting power in three months," Crowley said.
Switzerland represents US interests in Iran.
"What that tells us is that ... our three American citizens are potentially in deplorable conditions," Crowley said. "We will continue to press the Iranian government so that we can see for ourselves, you know, what the conditions of our citizens are."