Sgt. Khanh T. Nguyen is a man without a country fighting for the United States.

Born in the Republic of South Vietnam, which no longer exists, and twice denied U.S. citizenship, Nguyen has been fighting two wars: overseas against Saddam Hussein's regime and here against immigration officials who say he does not have the moral character to be a U.S. citizen.

Nguyen's citizenship was denied because he omitted information on his application about arrests when he was a juvenile.

"I have spent my entire adult life earning my citizenship by serving the United States of America honorably and well as a United States Marine," Nguyen, 30, wrote in a November letter to the Bureau of Citizenship and Immigration Services. "Please grant me the opportunity to clear my name and become a United States citizen."

Nguyen has even pleaded his case on national television, in an April 3 interview with a Fox News Channel reporter embedded with his unit somewhere in the Iraqi desert. The unit, the 4th Light Armored Reconnaissance Battalion, 4th Marine Division, had seen combat the day before with Iraqi soldiers who had fired rocket-propelled grenades, mortars and small arms. It was the battalion's second battle with Iraqi forces in a matter of days.

"I honestly want to believe when this is all over, that I've earned my citizenship," Nguyen said during the interview.

Nguyen, a Marine Corps Reservist who lives in Silver Spring, is one of almost 13,000 noncitizens in the military reserves, along with more than 37,000 active-duty U.S. military personnel who are noncitizens.

The immigrant soldiers entered the spotlight as soon as Operation Iraqi Freedom began. Several of the first U.S. casualties in the war were noncitizens, and seven have been awarded U.S. citizenship posthumously.

In recent days, several religious leaders and elected officials have urged the Bush administration to grant immediate citizenship to immigrant soldiers while they are on the war's front lines.

"There is something terribly wrong with our immigration policies if it takes death on the battlefield to earn citizenship," Cardinal Roger M. Mahony of the Archdiocese of Los Angeles wrote to President Bush on April 7.

Rep. Hilda L. Solis (D-Calif.) and Sen. Harry M. Reid (D-Nev.) last week introduced legislation to make it easier for active military personnel and reservists to become U.S. citizens. Rep. Richard Hastings (R-Wash.) introduced a bill making active-duty immigrants immediately eligible for citizenship. And Sens. Zell Miller (D) and Saxby Chambliss (R), both of Georgia, introduced a bill to grant immediate citizenship to noncitizen soldiers who die in combat. That bill was approved by the Senate Judiciary Committee on Thursday.

Nguyen immigrated to the United States in 1973 at the age of 6 months with his sister and mother, who had married a U.S. serviceman, and grew up in Phoenix. As a legal permanent resident of the United States, he enlisted in the Marine Corps upon graduating from high school and served for six years. He was discharged honorably in 1997. In 1999, he and his fiancee, Anneli Nilsson, moved to Silver Spring and he joined a Marine Reserve unit based in Frederick.

A year later, Nguyen applied for U.S. citizenship under a provision that allows noncitizens who have served at least three years of active military duty to naturalize. But he made a mistake: He denied that he had ever been arrested.

In fact, he had been charged with a schoolyard assault, shoplifting and being in possession of alcohol as a minor when he was about 15. He had revealed all this, and the fact that he had tried marijuana once, in his Marine Corps enlistment package. Immigration officials had access to Marine records when investigating Nguyen's background for citizenship.

When he was interviewed in October by immigration officials, Nguyen denied being arrested.

After his application was denied, he wrote in a November letter asking for a hearing: "I was not even thinking about the trouble that I got into as a child. It was never my intention to deceive. My mistakes are well documented, and I feel that I have since more than made up for them."

Nguyen received overseas deployment orders Jan. 31, and he managed to get a hearing on his citizenship denial Feb. 4. His unit left for Camp Lejeune, N.C., Feb. 7 and for Kuwait on Feb. 22. He was denied citizenship a second time in a letter dated March 20 that Nilsson opened at their Silver Spring home.

Immigration officials say that Nguyen's teenage offenses, if he had declared them, would not have provided grounds for rejection of his citizenship application. But his misstatement did.

"He didn't provide accurate information," said Bill Yates, associate director for operations in the Bureau of Citizenship and Immigration Services.

Yates said Nguyen may reapply for citizenship when he returns from overseas duty, under an order signed by Bush last year and made retroactive to Sept. 11, 2001, to expedite citizenship for military personnel who serve in active duty during the U.S. war on terrorism.

Yates said soldiers who apply under the executive order "only need to establish good moral character for the year prior to the filing of the application."

Nilsson acknowledges that her fiance made a mistake. But she believes, as he does, that he has proved his good character.

"He joined the Marine Corps to pay the United States back for taking him in as a baby, and the only thing he ever wanted, that I've heard him say, was to be a Marine and to be a U.S citizen," Nilsson said. "He feels that he has earned it."

Marine Sgt. Khanh T. Nguyen with his fiancee, Anneli Nilsson. His application for citizenship was denied because he omitted information about juvenile arrests.