American pastor Saeed Abedini, who is serving an eight year prison sentence in Iran, is being treated like a "pawn in a game of chess," his wife has said, following the Iranian president's offer to release him in return for Iranians being held in the US.

Naghmeh Abedini, who has campaigned for her husband's release since his detention in 2012, told Fox News that President Rouhani's offer was offensive.

Three US citizens are currently imprisoned in Iran – pastor Saeed, Washington Post journalist Jason Rezaian and US Marine Amir Hekmati. Rouhani told CNN on Monday that they may be released if the US "take[s] the appropriate steps" to free the 19 Iranians currently in US custody.

"If the Americans take the appropriate steps and set them free, certainly the right environment will be open and the right circumstances will be created for us to do everything within our power and our purview to bring about the swiftest freedom for the Americans held in Iran as well," Rouhani said.

"If the Americans take the appropriate actions vis-a-vis Iranian citizens who are being imprisoned here, then the right atmosphere and environment will be created for reciprocal actions, perhaps."

Following this statement, Naghmeh Abedini, who is in New York during the UN General Assembly to lobby on behalf of her husband, condemned Rouhani's words.

"My husband is not collateral. He is a father and a man who broke no law. Yet, Iran is treating him like a pawn in a game of chess," she said.

"President Rouhani's demand that America release 19 criminals in exchange for his consideration of releasing individuals like my husband, imprisoned solely for his faith, demonstrates that the Iran of today is no different than the Iran who took Americans hostage during the Iranian revolution."

Pastor Saeed is being held in Iran's notorious Rajai Shahr prison on charges of undermining national security. Reports surfaced last week that intelligence officers have now claimed he is connected to anti-government groups and has taken action against the Iranian government, charges the pastor denies.

Abedini began developing home church communities for Christian converts, who are forbidden from gathering in Iran's public churches, more than a decade ago. He was first arrested in 2009, but was later released after pledging to stop formally organising house churches.

He was arrested for a second time upon returning to Iran in 2012 to help build a state-run, secular orphanage and was held without charges until January 2013, when he received his eight-year sentence. There are now concerns that this sentence will be extended.

Naghmeh Abedini, who met with Obama privately earlier this year to discuss her husband's situation, had previously urged the administration to secure the release of US prisoners in Iran as part of the nuclear deal agreed between Iran and six major world powers in July.

Jordan Sekulow, executive director of the American Center for Law and Justice, which represents the Abedini family, said yesterday that those campaigning on behalf of the prisoners maintain this should have been the case.

"It's been our position from the beginning that the release of Pastor Saeed and the other imprisoned Americans should have occurred before any nuclear agreement was reached with Iran," he said.

"Unfortunately, that did not occur and in our view we lost a lot of bargaining power by not securing the release of Pastor Saeed and the others earlier. Now, it is an uphill battle."