WASHINGTON (AFP) – The 1,200 National Guard soldiers deployed to the US border with Mexico last year will remain on their jobs until late September, a US official said Friday.

The administration has now "extended the temporary deployment of National Guard personnel... through September 30, 2011," Department of Homeland Security spokesman Matthew Chandler told AFP.

The extension keeps the soldiers three months beyond their original withdrawal date.

President Barack Obama sent the National Guards soldiers to the border last year to help crack down on smuggling and drug trafficking.

The deployment was designed to provide a one-year bridge to give US Customs and the US Border Patrol time to hire and train about 1,000 more agents.

The Guard is "providing support to law enforcement functions aimed at stemming northbound and southbound illicit smuggling and flows of people, drugs, weapons, and bulk cash," Chandler said.

The National Guard soldiers worked mostly observing suspicious movement along the 2,000-mile-long (3,200 kilometer) border and relaying any information back to Border Patrol agents, while other guard troops worked as criminal and intelligence analysts.

The soldiers, working with the civilian agencies, have helped in the capture of more than 6.3 tons of drugs and helped detain more than 7,000 illegal immigrants, Chandler said.