McALLEN, Texas (AP) -

A top National Guard general says most of the 1,000 troops heading to South Texas will take up observation positions along the border and detain people only if they interfere with their mission.

Texas Adjutant General John Nichols told The Associated Press on Tuesday that the troops will help deter illicit traffic amid a record spike of unaccompanied minors crossing the border. Republican Gov. Rick Perry announced the Guard's involvement Monday.

Nichols said troops will be armed for their safety. They will try to avoid detaining people and instead refer people to state troopers. State troopers could arrest people for a state crime or call Border Patrol if they entered the country illegally.

Nichols said training begins immediately to cover scenarios such as immigrant children turning themselves in.