Five members of Congress say the U.S. State Department is not doing enough to help Pastor Saeed Abedini, an imprisoned U.S. citizen being held in an Iranian prison because of his Christian beliefs.

"To date, the State Department's posture on this case has been woefully inadequate, especially given that the life of an American citizen hangs in the balance," their March 20 letter said.

"Both the European Union and the United Nations special rapporteur on human rights in Iran have advocated publicly for Pastor Saeed – the same cannot be said of this administration."

Those who signed the letter to Secretary of State John Kerry included Rep. Frank Wolf (R-Va.), co-chair of the Tom Lantos Human Rights Commission of the House Committee of the House Committee on Foreign Affairs.

The letter charged that the absence of State Department testimony at a recent hearing "sent a dangerous message" that "even human rights that compromise the safety and security of American citizens will be met with virtual silence from the U.S. government."

Pastor Abedini is serving an eight-year sentence in Iran's harsh Evin Prison. He converted to Christianity from Islam 13 years ago and had worked with house churches in Iran until attracting government opposition. In 2009, he agreed to stop working with house churches and he began work in non-religious orphanages.

He was arrested in September 2012 on charges that his earlier work with house churches posed a threat to national security.

The pastor has been a U.S. citizen since 2010, following his marriage to his American wife. He has the support of legal groups like the European Centre for Law and Justice and the American Center of Law and Justice, which have helped collect nearly 450,000 petition signatures in support of Abedini.

In a February letter, the pastor reported that in prison he has suffered physical violence, psychological abuse, death threats and declining health.

Last week the Tom Lantos Human Rights commission held a hearing about religious freedom abuses in Iran with a specific focus on the Abedini case. The State Department said no one was available to testify.

"There was a palpable sense of disappointment in the room that our government didn't deem the hearing important enough to provide a witness," said the congressmen's letter.

State Department officials met with Rep. Wolf's staff and Abedini's wife and her legal counsel later that day. Wolf said these officials would have made suitable witnesses for the hearing.

Reps. Trent Franks (R-Ariz.), Mike Simpson (R-Idaho), Robert Aderholt (R-Ala.), Rep. Raul Labrador (R-Idaho) and Chris Smith (R-N.J.) also signed the letter.

They charged that the State Department "misled" the commission. They urged Kerry to issue a public statement advocating Pastor Abedini's "immediate and unconditional release" and to use the full resources of the U.S. government to free the pastor.

The congress members said an earlier State Department statement that expressed disappointment at Abedini's sentence failed to convey "an appropriate sense of urgency."

They also backed a proposal to create a special envoy at the U.S. State Department to advocate on behalf of religious minorities in the Middle East and South Central Asia. In the last congressional session, the proposal passed in the House but failed to advance in the Senate Foreign Relations committee, which Kerry headed at the time.

Rep. Wolf earlier this month released a report on the persecution of Christians, Jews and other religious minorities in the Middle East and south central Asia that lamented that persecution was causing a Christian exodus from the Middle East.