TORONTO -- An American soldier who fled to Canada after she became disillusioned with the Iraq war is weighing her legal options after a ruling that would have her deported to the U.S.

"My biggest fear is being separated from my children and having to sit in a prison for politically being against the war in Iraq," Kimberly Rivera told a news conference Friday.

Rivera was joined by a number of groups, including the War Resisters Support Campaign, Amnesty International and the Canadian Labour Congress, who urged Immigration Minister Jason Kenney to let Rivera, her husband and their four children stay in Canada.

Rivera's lawyer Alyssa Manning said her client is considering appealing the ruling on her pre-removal risk assessment, which has ordered that she leave Canada by Sept. 20.

Manning said federal officials failed to consider the fact that Rivera has been outspoken about her opposition to the Iraq war when they evaluated her assessment.

Although the majority of those who flee the U.S. military are not jailed, the small percentage of soldiers who get sent to prison are those who are outspoken about their beliefs, said Manning.

"The risk that Kim faces as a public critic of the Iraq war has not been considered properly," said Manning.

"We have spoken with the command at Fort Carson and they have explained to the Rivera family that they have every intention of detaining and then prosecuting (Rivera) upon her return."

Manning said she expects Rivera would be sent to jail for two to five years.

But a spokeswoman for Immigration Minister Jason Kenney said the federal government does not believe the U.S. subjects its soldiers to persecution.

"Military deserters from the United States are not genuine refugees under the internationally accepted meaning of the term," said Alexis Pavlich, the minister's press secretary, in an email.

"These unfounded claims clog up our system for genuine refugees who are actually fleeing persecution."

Rivera is also considering asking the government to delay her deportation while her humanitarian and compassionate grounds application is still being weighed, said Manning.

"That application raises concerns such as the best interests of the four minor Rivera children," said Manning.

Rivera, who lives in Toronto with her family, came to Canada in 2007 to avoid further military service. She had initially arrived while on leave but then applied for refugee status.

Rivera said she grew to oppose the Iraq war while she was taking part in it, and even stopped carrying her rifle with her.

"I got in trouble for not carrying my rifle, so then I just secretly stopped carrying my ammunition," said Rivera.

The War Resisters Support Campaign said two other Iraq war resisters who were deported, Robin Long and Clifford Cornell, faced year-long jail sentences upon their return.