US Border PAtrol
© AP Photo/Eric GayImmigrants suspected of crossing into the United States illegally along the Rio Grande near Granjeno, Texas, are held by U.S. Customs and Border Protection agents.
The U.S. Border Patrol is losing agents faster than it can hire them, according to a new audit released Wednesday that said competition with other federal law enforcement and the difficulty of passing a polygraph test have sapped the agency of nearly 2,000 agents it's supposed to have.

More than 900 agents leave each year on average but the Border Patrol only hires an average of 523 a year, the Government Accountability Office said in a broad survey of staffing and deployment challenges at the key border law enforcement agency.

The law requires the agency to have a minimum of 21,370 agents on board, but it had just 19,500 agents as of May.

That's an even bigger problem when stacked up against President Trump's call for hiring 5,000 more agents, to reach a workforce of 26,370.

Managers blamed everything from remote working conditions to competition with U.S. Immigration and Customs Enforcement, the interior immigration agency that's also staffing up, for difficulty in filling out ranks.

Problems span the southwest border, with eastern California and western Texas suffering particular shortages.