Congressman Frank Wolf, R-Va., told Congress Tuesday Iraqi Christians are facing a "genocide" and horrific crimes against humanity.
Wolf said the so-called Islamic State "is systematically targeting Christians and other religious minorities in Iraq for extinction."
Hundreds of Christians have been fleeing from Mosul, Iraq's second biggest city. Last week the Islamist group gave Christians three choices: convert to Islam, pay the jizyah tax required of non-Muslims or face execution.
Meanwhile, IS insurgents stole nearly everything from the Christians they threatened to kill.
Those who fled had to to leave most of their belongings behind. Then gunmen at checkpoints set up by the IS stole most of what they managed to take along.
"Where is the Obama administration?" Wolf asked, citing a letter sent to the president by Congress in June.
"The Obama administration has to make protecting this ancient community a priority. It needs to encourage the Kurds to do what they can protect those fleeing ISIS and provide safe refuge. It needs to ensure that of the resources going to the region, a portion be guaranteed to help the Christian community," the letter stated.
"The time to act is now," Wolf said, noting this past Sunday was the first one in 1,600 years without a Christian Mass in Mosul.
On Sunday, jihadists seized the 1,800-year old Mar Behnam Monastery, about 15 miles south of Mosul. The resident clergymen fled to the nearby city of Qaraqoush.
"Even here in Qaraqoush, we do not feel safe because IS militants are only few kilometers away," said Father Sherbil Issou, a priest who fled Mosul.
Noel Ibrahim, who fled the city with his family last week, said IS gunmen stopped cars and stole cash and gold jewelry from the women.
"One of the gunmen told us, 'You can leave now, but do not ever dream of returning to Mosul again,'" Ibrahim said.