WASHINGTON — Sister Diana Momenka, a Catholic nun from Iraq, intended to visit the U.S. to talk about the persecution of religious minorities in her country — until the local U.S. consulate denied her visa application.

Now, the Department of State is facing questions about whether that action has interfered with efforts to help persecuted Christians and other minorities.

“Sister Diana represents tens of thousands of Iraqi Christians, forced to convert or die or flee their homes. She’ll tell us the truth about what’s happening,” U.S. Rep. Doug Collins, R-Ga., told CNA May 7.

“Like thousands of other Christians in the region, Sister Diana is a victim of ISIS,” Collins said in a May 5 letter to Secretary of State John Kerry. “She has devoted her life to helping other victims and advocating for them.”

Collins, a member of Congress’ Tom Lantos Human Rights Commission, is investigating the rejection of her visa application. He said the State Department’s actions indicate that it does not believe sharing her story with policymakers and others “merited even the consideration of her application.”

“Rather, it appears the State Department has chosen to continue to largely ignore the persecution of Christians at the hands of ISIS,” he charged. “I find that unacceptable.”

Sister Diana, a Dominican Sister of St. Catherine of Siena, intended to take part in an Iraqi delegation to Washington. She was to meet with the Senate and House Foreign Relations Committees, the State Department, the U.S. Agency for International Development and several non-government organizations, according to Nina Shea, writing at the National Review blog The Corner on May 3.

Her visit had the endorsement of U.S. Rep. Anna Eshoo, D-Calif., and was supported by two groups involved in international human rights.

On April 28, the U.S. consulate in Erbil told the nun that her visa application had been rejected. Sister Diana told Shea that a consular officer said that the visa was denied because she was an internally displaced person.

Displaced persons are considered at risk of overstaying their visas or otherwise seeking to remain in the U.S. However, this status is not always a barrier: According to Shea, a delegation of internally displaced Iraqi Yazidis received visas in October to travel to the U.S. to speak.

Sister Diana had been a teacher at St. Ephrem Seminary in Bakhdida until the Islamic State invaded the city in August 2014. The caliphate forced Christians to flee if they would not convert to Islam or pay the tax on non-Muslims.

Like tens of thousands of other Christians, Sister Diana has fled to Iraqi Kurdistan for her safety. She has been teaching at Babel College of Philosophy and Theology in Erbil.

She was the only Christian in her delegation, which also included members of the Yazidi and Turkmen Shia religious groups.

Sister Diana’s visa application was the only one rejected.

A State Department spokesman told CNA the department cannot discuss individual visa applications due to privacy concerns.

Shea said that, “as an articulate, English-speaking Iraqi Christian, who is not only personally a victim of ISIS, but also an aid worker with a broad perspective on the suffering of the Christian community there, Sister Diana would make an exceptional witness.”

CNA sought comment from Sister Diana, but she was unable to respond by deadline.

Collins said Sister Diana did not appear to be at high risk of remaining in the U.S. beyond her visa period. His letter noted her previous travels to the U.S. and asked why the State Department would bar a persecuted Catholic nun from coming to the U.S. to speak about her experiences and to advocate for religious freedom.

Collins told CNA that his job on the Lantos Human Rights Commission is to focus on issues of religious persecution and religious freedom that he believes the U.S. administration “refuses to recognize.”

“Islamic radicalism is real, and so is its conquest of religious minorities in the Middle East and Africa,” he said, charging that Kerry and President Obama are failing to talk about the persecution of Iraqi Christians.