Washington ? The Obama administration formally asked Congress Tuesday for $600 million in emergency funds to hire another 1,000 Border Patrol agents, acquire two aerial drones, and enhance security along the Southwest border.

The proposal also would provide funding for an additional 160 Immigration and Customs Enforcement agents and extra Border Patrol canine teams, according to a senior White House official who spoke on condition of anonymity because he was not authorized to speak publicly.

In a letter to House Speaker Nancy Pelosi, President Barack Obama said his request “responds to urgent and essential needs” and asked that it be considered as an emergency.

“These amendments would support efforts to secure the Southwest border and enhance federal border protection, law enforcement and counternarcotics activities,” Obama wrote.

The president’s request also would provide funds for extra FBI task forces, Drug Enforcement Administration agents, prosecutors and immigration judges.

Some of the funds would go to help Mexican authorities, such as with ballistic and DNA analysis, the White House official said. Mexico is under siege from drug cartels, and border states are concerned that the violence will spill into the United States.

Arizona Gov. Jan Brewer, who met with Obama last month after signing a state immigration law, has called her state “the gateway to America for drug trafficking, extortion, kidnapping and crime.” She has blamed the federal government for failing to secure the border and has lobbied for stepped-up law enforcement resources and unmanned aircraft.