PHOENIX -- Immigration and Customs Enforcement officers and the Maricopa County Sheriff's Office will be teaming up to fight illegal immigration.

According to the 287G agreement, sheriff's deputies will be allowed to act as federal agents when arresting illegals.

Special agent in charge Alonzo Pena told KTAR of the importance of this agreement.

"For ICE, the partnership we form with the state and law enforcement authorities is crucial to our law enforcement strategies and homeland security."

Sheriff Joe Arpaio's goal is to have 160 deputies trained in the next several months.

"So not only will we be enforcing the state law and we will continue to do that. In fact I'm going to get tougher on the state law. That will not stop," said Arpaio. "Now we have this added tool which will be very, very important."

The first group started training Tuesday.

Deputies will go through a four-week course to learn about nationality and immigration laws in depth.

The trained officers will have authority to determine whether someone is an illegal immigrant and will be able to designate that immigration removal proceedings begin.

Opponents and critics fear it could result in racial profiling.