PHOENIX (AP) - An Arizona lawmaker on Thursday proposed giving Gov. Janet Napolitano $10 million to pay for sending National Guard troops to the state's border with Mexico to detain illegal immigrants.

Nearly 2,400 National Guard members are already at the state's border to perform support duties that tie up Border Patrol agents, but the soldiers aren't authorized to make arrests. Support duties include monitoring border points, assisting with cargo inspection and operating surveillance cameras.

Republican state Rep. Warde Nichols of Chandler, an advocate for tougher immigration enforcement, wants an additional 100 border troops who would be able to detain immigrants if the governor used the National Guard in a state of emergency at the international boundary.

Nichols said the proposal was needed because the current approach is too restrictive and leaves Guard members vulnerable to armed criminals.

He has criticized the decision by four National Guard troops on Jan. 3 to back off and call in Border Patrol agents as gunmen approached their post near the Arizona-Mexico border. "They are basically in a position where they cannot defend themselves until fired upon," Nichols said.

Democratic Rep. Steve Gallardo of Phoenix, a supporter of the actions of the troops in the Jan. 3 incident, said the proposal was politically motivated and wasn't going to solve the state's immigration woes.

"It is painfully obvious that the Republicans are obsessed with trying to make the (Democratic) governor look bad," Gallardo said.

Napolitano said Wednesday that the proposal wouldn't be a wise use of the National Guard. "It's being effective," she said of the Guard's current border work. "(The Guard is) being employed in a very useful way. It has freed up hours and hours and hours of Border Patrol time."

Last year, the governor vetoed a bill by another lawmaker that would have required her to send National Guard troops to the border if she declared a border emergency.

Napolitano, who at the time was pushing a plan to send troops to the border to assist federal authorities, objected to the bill's requirement that she send troops to the border - a mandate that she said was an unconstitutional infringement of her powers to command the National Guard.

At a news conference Thursday, Nichols said last year's bill would have called troops to the border to detain immigrants.

Told later in the day that a review of last year's bill found no such language, Nichols said the assumption was that the proposal would have put troops at the border to detain immigrants.