A scant 35 people were taken into custody during a long-threatened U.S. enforcement action that targeted more than 2,100 immigrants who had been ordered deported, the head of U.S. Immigration and Customs Enforcement said on Tuesday.

Of those arrested, 18 were members of families and 17 were collateral apprehensions of people in the country illegally encountered by U.S. Immigration and Customs Enforcement officers. None of those arrested resulted in the separation of family, officials said.

The operation was originally scheduled for June for a dozen major U.S. cities and was highly publicized, which likely contributed to the low rate of arrests, acting director of ICE Matthew Albence said on a call with reporters.

The operation targeted families centered on those who had been ordered deported by an immigration judge in 10 cities around the country who were subjected to fast-track proceedings. It was canceled once after media reports telegraphing when and where it would begin, though Trump announced it would be postponed following a phone call with House Speaker Nancy Pelosi who urged him to do so.

The second effort began July 14 and again was met with media attention noting where and when it was to start, including from Trump who announced the date.

Trump described the action over the July 13 weekend, dubbed "Operation Border Resolve," as "very successful" even though much of the activity was not visible to the public.

Albence said the overall publicity caused problems for an operation that relies largely on secrecy and surprise, adding the publicity made some officers targets, and they had to be pulled off. More than 3,000 businesses were notified by ICE that they will be audited and could face criminal charges stemming from employment of illegal immigrants, according to Albence.

Immigrant rights activists nationwide pushed "know-your-rights" campaigns hard, using hotlines, text networks, workshops, social media and a smartphone app to notify family members in case of an arrest.

A separate nationwide enforcement operation targeting immigrants illegally who had criminal convictions or charges netted 899 arrests. And officers handed out 3,282 notices of inspection to businesses that may be employing people here illegally.

Trump is delivering on his campaign promises to crack down on illegal immigration, a signature policy objective of his administration. He has pushed Guatemala, Mexico and other countries in the region to act as buffer zones and take in asylum seekers who would otherwise go to the United States.

(With input from Reuters and AP)