Arrests of suspected illegal immigrants are up 43 percent in the first half of 2017 from the same period last year, Department of Homeland Security officials said. The DHS branch Immigration and Customs Enforcement made 91,000 arrests during the first seven months of the year, they said.
"Going from 5 miles of fence to 60 miles of fence on the Yuma border made a huge difference," a senior DHS official said in a conference call with media, speaking on condition of anonymity.
Increased enforcement, including this year's extension of the fence, resulted in an 83 percent drop in illegal border crossings near Yuma since 2007, the official said. Up to 800 immigrants illegally crossed the border in the area every day in 2005 and 2006, the official said.
The DHS officials said 126,472 apprehensions have been made in the first half of this year, a 46 percent increase from the first half of 2016.
Away from the border, removals in the interior of the country are up 32 percent this year from last year, the officials said.
"There are 500,000 immigration fugitives and criminal aliens that ICE cannot reach or arrest" due to available resources and sanctuary city protections, another senior DHS official said on the call.
As a candidate, Trump pledged to crack down on illegal immigration and build a wall on the U.S.-Mexico border to deter people from coming into the country. The wall expansion has proven slow, and Mexico's president has rejected Trump's call that Mexico pay for the barrier.
Trump has repeatedly cited arrest statistics as evidence that his strategy is working.
— CNBC's Jacob Pramuk contributed to this report.