Arizona Gov. Jan Brewer refused to flinch after Obama administration officials confirmed Friday that they plan to file a lawsuit challenging the state's anti-illegal immigration law.

In a statement issued late Friday, Brewer called Obama's decision "outrageous" but "not surprising."

"Our federal government should be using its legal resources to fight illegal immigration, not the law-abiding citizens of Arizona," she said.

Meanwhile, Arizona Attorney General Terry Goddard said his office plans to withdraw as the state's lawyers in legal challenges to the law, leaving Brewer's attorneys to defend it. Brewer had complained that Goddard's criticism of the measure raised doubts about his ability to defend it.

Brewer said with Goddard out, "I will ensure the immigration laws we passed are vigorously defended all the way to the United States Supreme Court if necessary, where this reasonable law will ultimately be found constitutional."

The law takes effect July 29 and requires officers to question a person's immigration status if there's a reasonable suspicion that he or she is in the country illegally.

At least five legal challenges have been filed to the law since April.

The lawsuits generally allege that Arizona's law will lead to racial profiling and argue that it's the federal government's responsibility to regulate immigration.

On Friday evening, Brewer's defense team asked a federal judge to throw out the suit by the American Civil Liberties Union and other groups that challenge the law's constitutionality.

Obama officials confirmed plans to file their lawsuit after Secretary of State Hillary Clinton said in an interview with a TV station in Ecuador earlier this month that the administration would challenge the law in court, though officials had long said the issue was under review.

Administration officials initially would not confirm Clinton's statement. But an official told Fox News on Friday that while the review is still underway, the decision has already been made that a Department of Justice suit will be filed. The administration at this point is just building its case.

Another official said there are still "substantial" issues to address and work out before the Justice Department knows that it has a strong enough case to file a lawsuit. The official said the department intends to file suit, but that any court action is contingent on the final review.

Clinton's announcement was met with outrage Thursday by Arizona Gov. Jan Brewer, who signed the law. Brewer told Fox News she's ready for a fight.

"What a disappointment," Brewer told Fox News' Greta Van Susteren on Thursday, saying she was shocked the administration would make such an announcement on foreign TV without giving Arizona officials the news first.

"We are not going to back away from this issue," Brewer said. "We are going to pursue it, we're going to be very aggressive," Brewer said. "We'll meet them in court ... And we will win."

She added: "The population of America agrees with Arizona."