US citizen Pastor Saeed Abedini will celebrate his birthday, Thursday, May 7, in his Iranian jail cell.

Pastor Abedini has been imprisoned for over two and half years on charges of proselytising and posing a perceived national security threat against Iran.

On Thursday, which is also the National Day of Prayer in the United States, Abedini turns 35 years old. Although still far from his loved ones and facing reported continued abuse and daily beatings by his guards, the American Center for Law and Justice says Abedini has only one wish: a revival of prayer in America.

"Remember my chains in your freedom and chain together in unity for our beloved America," Abedini urged in an open letter of prayer he has asked Christians across America to read on his birthday.

Referencing scripture from the book of Ezra, Abedini asks American Christians to reflect on their freedom to gather, pray and influence leadership toward a greater revival of faith in the US.

Current negotiations on a nuclear agreement between the US and Iran continue to develop, but a potential requirement to free Iran's captive American citizens prior to its finalisation may not be included.

In addition to Abedini, Iran holds three other Americans - Jason Rezaian, Amir Hekmati, and Robert Levinson - on various charges. Although President Obama called for Abedini's release on March 20 - the Persian New Year holiday, or Nowruz - the discussion of captive Americans appears to be an awkward interference to negotiations at this time.

In his letter, Abedini lamented, "So many Christians around the world are imprisoned and martyred for their faith in Jesus."

However, he drew on the strength of the believers in Ezra chapter 10 and how the people gathered together despite the heavy rain and cold.

"People should stand under any pressures to pray for their nation, for the Lord to bring revival," he said.

As Christians observe May 7's National Day of Prayer and Pastor Abedini's birthday, petitions are being circulated demanding his freedom and supporters are being asked to contact representatives to pressure the U.S. Government in pressing for his release. The ACLJ's petition has so far been signed over 214,000 times.

The request for prayer was provided within the context of an open letter, with accompanying Farsi translation, and is available in full on the ACLJ website.