The first of 532 National Guard troops are set to begin their mission in the southern Arizona desert on Monday under President Barack Obama's plan to beef up U.S.-Mexico border security, although they won't have any law enforcement authority.

About 30 troops will start their jobs on the border Monday, and waves of more troops will be deploying every Monday until all 532 are expected to be on the Arizona border by the end of September. In May, Obama ordered 1,200 National Guard troops to boost security along the border.

California Gov. Arnold Schwarzenegger has said the first of 224 National Guard troops allocated for his state have finished their training and are expected to be deployed to the state's border on Wednesday.

Troops in New Mexico were in different stages of training and don't yet know when they'll be deployed on the border. A Texas National Guard spokesman did not immediately return a call for comment.

The troops will be "extra eyes and ears" for U.S. Customs and Border Protection agents, and though they will have guns for self-defense, they will not have the authority to arrest anyone, said Arizona National Guard spokesman Lt. Valentine Castillo.

He said if troops spot illegal immigrants, they must report them to the Border Patrol, whose agents would make the arrest.

The troops will be stationed in the desert at "strategic locations" along the border, he said, but did not provide specifics.

Mario Escalante, a spokesman for the Border Patrol's Tucson sector, said the troops will use binoculars, night-vision equipment, remote cameras and computers to conduct surveillance on the border, and will have radios to communicate with Border Patrol agents.

They'll be set up at high points in various locations in the desert, he said.

"Having those resources and deploying them adequately makes us more effective," he said.

Obama was all but compelled to act on illegal immigration after the passage of a tough new Arizona law thrust the border problem into the public spotlight.

Arizona Gov. Jan Brewer cited government inaction when she signed the law, which reignited that national illegal immigration debate, caused the governor's popularity to soar in the state and turned her into a national figure.

The law went into effect July 29 after a judge ruled to block its most controversial sections, including a part that required officers to check a person's immigration status while enforcing other laws. Brewer is appealing the decision and says she'll take it all the way to the Supreme Court.

Brewer has been a sharp critic of the National Guard deployment, saying the troops aren't enough and that Obama should have sent 6,000 along the border, half of them to Arizona.

But in March 2009, Brewer wrote Defense Secretary Robert Gates asking for 250 National Guard troops, less than half the amount now being sent.

Brewer spokesman Paul Senseman did not immediately return a call for comment Friday afternoon.

Santa Cruz County Sheriff Tony Estrada, whose territory is along the Mexico border and includes Nogales, said any additional manpower on the border is welcome and will help.

"It's definitely a start," he said. "Any more boots on the ground, they'll make things safer and it'll make the border more secure, especially for the Border Patrol — they have a humongous task out there, not only with illegal immigration but drugs."

But he said there'd have to be "thousands and thousands" of troops on the border to come close to having any major impact on illegal immigration.

"The border will never be sealed," he said. "They'll find ways to go under it (through tunnels), go through ports of entry with false documents or false claims; they find ways of going over, and they find ways to go around it."

Former President George W. Bush sent 6,000 National Guard troops to the border in June 2006, and they also had no arrest power. Those troops were pulled out in July 2008.