(CNN) Immigration and Customs Enforcement arrests dropped this year as resources and attention were diverted to the surge of migrants arriving at the southern border, according to newly released data.

ICE made around 143,000 arrests in fiscal year 2019, down around 10% from nearly 159,000 arrests the previous fiscal year, which starts on October 1 and runs through September of the following year.

"What this means in real numbers and in real life and with real victims that there are 13,000 fewer criminals that we arrested this year than we arrested last year," said acting ICE Director Matthew Albence during a press conference Wednesday.

The decline in ICE arrests is indicative of the influx of migrants arriving at the US-Mexico border this past year. According to the agency, limited resources and the volume of people who entered the United States strained ICE's ability to arrest undocumented immigrants already living in the country.

President Donald Trump has vowed to crack down on illegal immigration, and while his administration has rolled out a series of controversial measures aimed at doing so, he also had to contend with a growing number of migrant arrivals at the southern border.

Read More