(CNN) - Additional National Guard troops assigned to the Mexican border under President Barack Obama's border security initiative have started reporting to their posts, officials said Monday.
More than 30 National Guard members have begun their deployment as part of the administration's border protection plan, according to Special Agent Mario Escalante with U.S. Customs and Border Protection.
Troops will continue to arrive over the next two months, with an expected force of 532 members by the end of October, said Lt. Valentine Castillo of the Arizona National Guard.
Top Republicans - including Arizona Sen. John McCain and Arizona Gov. Jan Brewer - have repeatedly accused Obama of failing to provide sufficient security along the U.S.-Mexico border.