"It's been emotional," said Spc. Dung Van Nguyen, 24, holding his naturalization papers after a ceremony that earlier in the morning officials were unsure would take place because of a backlog of federal paperwork.

On Monday, Nguyen will leave Utah with the 120-member 155th Maintenance Company to Fort Bliss, Texas, for training.

"I joined because I wanted to help out the guys who are in Iraq," he said. "My unit is the best. Anything a soldier drives, we can fix."

Said his sister Tuyet Nguyen of his deployment: "Our parents can't sleep at night."

Nguyen was born in North Vietnam. After his father was jailed in their war-torn country, the family immigrated to Logan when he was 4 years old and then moved to Southern California.

"It was very hard living in Vietnam," said Tuyet Nguyen, of Logan. "We wanted freedom."

Dung Van Nguyen graduated from Salt Lake Community College with an associate's degree in computer networking.

He works in logistics with the Guard.

"He's a strong man," said his girlfriend, Jennifer Kay, of West Jordan. "He's incredibly responsible and very, very smart."

Nguyen said he hopes to marry Kay when he returns after his 18-month military stint.

"I couldn't marry her before I left," he said.

"There's always the chance that some soldiers won't be coming back."

Nguyen is among 12,000 service members sworn in as U.S. citizens since President Bush signed legislation two years ago that makes noncitizen GIs eligible for citizenship immediately if they served any time after Sept. 11, 2001.

Nearly 20,000 noncitizen GIs have applied for citizenship, said Mario R. Ortiz, Denver, district director of the U.S. Citizenship and Immigration Services.

The stumbling block for many noncitizen service members serving abroad was the last step in the naturalization process, the final interview and swearing-in, which could only be conducted in the United States, said Ortiz.

Last fall when a new law went into effect allowing naturalization ceremonies to be conducted at U.S. embassies, consulates and military installations overseas, about 150 GIs took the oath of allegiance to the U.S. Constitution at American installations in Afghanistan, Iraq, Germany, South Korea and Japan.

"Today the United States is not only your home, it is your country," said Bush in a tape played Friday at the Utah Guard headquarters and in naturalization ceremonies worldwide.

Nguyen, the second youngest in his family of nine surviving children, said he is the last to take the oath.

"I needed to do it before I left," he said.

"It's been on my mind for a long time."