The father of a woman who traveled from her home in Alabama to marry an Islamic State fighter filed a lawsuit against President Donald Trump's administration as part of an effort to get her and his 18-month-old grandson returned to the United States.

Lawyers acting for Ahmed Ali Muthana, a former diplomat at the United Nations for Yemen who is a naturalized U.S. citizen and lives in Alabama, argue in the lawsuit filed in federal court in Washington D.C. late Thursday that remarks by Trump and other senior White House officials claiming that Hoda Muthana, 24, who was born in Hackensack, is no longer a U.S. citizen – thus barring her and her son from re-entering the USA – are unconstitutional.

Trump, Secretary of State Mike Pompeo and Attorney General William Barr are named as defendants in the case. Trump said Wednesday that he had instructed Pompeo to deny Muthana re-entry. Pompeo said she was not a U.S. citizen and has no "legal basis" to be brought back to American soil from the Kurdish-run refugee camp in northern Syria where she is being held with her young son, named in the suit as John Doe Muthana.

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Muthana joined the Islamic State, also known as ISIS, in 2014 after telling her parents she was going to Atlanta as part of a field trip connected with her business studies at the University of Alabama at Birmingham.

Instead, she withdrew from college and used her tuition reimbursement to purchase a plane ticket to Turkey, according to court documents.

From Turkey, she traveled to Syria, where she married twice, both times to ISIS fighters who later died in combat. Muthana fled to the al-Hawl refugee camp in December last year amid the collapse of the ISIS caliphate in Syria and Iraq.

Hassan Shibly, a Florida-based legal representative for her family, told USA TODAY in an interview this week that Muthana now wants to return to the USA to take responsibility for her actions, and for the sake of her son. She accepts she would likely be charged with providing material support to terrorism and need to serve time in jail.

She has also expressed remorse for what she did and claimed that she was "brainwashed" into going to Syria and partly motivated by youthful "arrogance." If permitted to return, Muthana has vowed to help de-radicalize other Americans.

She said she expected "no problems" in returning to the U.S. despite Trump's pledge.

"I know in fact that I was a citizen," Muthana told NBC News on Friday from the refugee camp in Syria where she's being held. "I prefer America to anywhere else," she said, adding that if she returns, "Of course, I will be given jail time."

However, the Trump administration has determined, apparently unilaterally without taking any action in courts or formally moving to revoke Muthana's citizenship, according to her father's lawsuit, that New Jersey-born Muthana never qualified for U.S. citizenship because at the time of her birth her father was a diplomat.

A person born in the U.S. to a foreign diplomat is not subject to U.S. law and is also not automatically a U.S. citizen at birth, according to the Immigration and Nationality Act.

But Ahmed Ali Muthana's lawyers for the suit, the Constitutional Law Center for Muslims in America, a Texas-based group, argue Trump, Pompeo and Barr are misinformed and that Muthana was in fact born after her father left diplomatic service.

Shibly, the family's Florida-based legal representative, shared with USA TODAY an official UN document apparently substantiating this claim. The plaintiffs also argue that the U.S. immigration authorities previously accepted this document from the UN as the basis from which to issue Muthana a U.S. passport in 2005 and then renew it in 2014.

The plaintiffs argue further, citing the Fourteenth Amendment to the U.S. Constitution – "all persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and the State wherein they reside" – that only the courts can decide whether a diplomat and/or family members are immune from this jurisdiction, not a "unilateral determination by the government."

In other words, Muthana can't just immediately lose her citizenship and be prevented from returning to the U.S. because Trump, Pompeo, Barr and others in the current administration say she should. There needs to be a legal process.

The plaintiffs say a letter addressed to Muthana at her parents' residence in Alabama in 2016, under President Barack Obama, when she was in Syria, informed her that her passport was being revoked, but that this letter, too, was based on an inaccurate understanding of the date on which her father's diplomatic position was terminated.

The lawyers also claim that if the U.S. government does not immediately help facilitate Muthana's return, her chance of ever returning faces "irreparable harm" because of the stated intention by Trump to withdraw U.S. military forces from Syria. The Syrian Kurds, who are fighting alongside U.S. troops, are running the camp where Muthana and an estimated 1,500 other foreign women and children are being held.

Muthana's case mirrors that of Shamima Begum, a 19-year-old British woman who is detained in the same camp in Syria. Begum married an ISIS fighter when she was just 15 and now wants to return to Britain to raise her young son, born last week.

The British government is trying to strip her of her citizenship in a move that her lawyer and family say would effectively render her stateless.

"It is problematic to revoke the citizenship of these young, disillusioned and now stateless people as it leaves them under the mercy of the Syrian regime or in the care of international organizations managing refugee camps," Reema Hibrawi, an expert on the Middle East at the Atlantic Council think tank, wrote in a blog post this week.

"If they have nowhere else to go or anyone to turn to, it is very likely they could rejoin ISIS in Syria or extremist groups elsewhere."