Immigration authorities are planning a massive roundup Sunday of undocumented families that have received deportation orders, two sources familiar with the matter told NBC News.

The raids will take place in several cities across the country and could target up to 2,000 immigrants facing deportation orders, the sources said.

Immigration and Customs Enforcement acting Director Mark Morgan confirmed the planned operation on Friday.

"This is not about fear," Morgan said in an interview with ABC News Live. "No one is instilling fear in anyone. This is about the rule of law and maintaining the integrity of the system."

Morgan said his agency will pursue more than 2,040 family members who are still living in the U.S. despite having received deportation orders. The goal, he said in the interview, was to deter others from entering the country illegally.

"Right now, the greatest pull factors for families to come here is they know that once they arrive in the U.S., they remain here untouched," Morgan said. "We have to change that."

Word of the planned round-up comes four days after President Donald Trump said ICE would soon deport "millions" of undocumented immigrants living in the U.S.

"Next week ICE will begin the process of removing the millions of illegal aliens who have illicitly found their way into the United States," Trump tweeted Monday night, less than 24 hours before officially opening his re-election bid with a rally in Orlando, Florida.

Two Department of Homeland Security officials told NBC News at the time that the “millions” figure the president used in his tweet was likely overblown.

On Friday, Morgan said there were no plans to conduct deportations in the millions. But he said it was necessary to target the undocumented families to maintain the "integrity" of the nation's immigration system.

"We're enforcing the law against all demographics," he told ABC News Live.

In recent years, deportations have dropped because U.S. authorities have run out of space to hold immigrants ordered to be shipped out of the country.

A sharp rise in migrants apprehended at the border has resulted in a lack of available bed space at ICE detention centers, leaving authorities with nowhere to hold any additional immigrants facing deportation orders.

Deportations peaked at around 400,000 a year at the beginning of this decade and decreased to about 250,000 or fewer undocumented immigrants annually in recent years, according to ICE statistics.