Washington (CNN) Acting US Citizenship and Immigration Services Director Ken Cuccinelli said Monday he did not know the details of Immigration and Customs Enforcement raids targeting undocumented immigrants despite speaking extensively on the matter in the days leading up to the widespread operation.

Cuccinelli had previously discussed the operation last week, but told CNN's Alisyn Camerota on "New Day" Monday that he did "not have operational details" and said Matt Albence, the acting director of ICE, has not reported to him on how many arrests were made in the raids, which began on Sunday.

Asked by Camerota why he did not know the details of the raids, Cuccinelli said, "presumably because operational details are kept contained within the agency executing the operation, as they should be."

"In terms of details of the operation and specific results, those are not public yet and I don't expect operational details to become public on the front side of their execution," Cuccinelli said at one point.

"I don't mean on the front side of their execution, I mean on the back side," Camerota replied.

"I told you, I don't have details about any arrests that have taken place so far with respect to that operation," Cuccinelli said.

Last week, however, Cuccinelli indicated to reporters at the White House that he was familiar with the operation.

"They're absolutely going to happen," he said then. "There's approximately a million people in this country with removal orders. And of course that isn't what ICE will go after in this, but that's the pool of people who have been all the way through the due process chain."

A senior administration official said Sunday that the operation had begun. Its aim: detaining and deporting about 2,000 undocumented immigrants who've been ordered removed from the United States in immigration courts.

The raids were slated for Atlanta, Baltimore, Chicago, Denver, Houston, Los Angeles, Miami, New York and San Francisco, a senior immigration official has said. New Orleans is also on the list, but the city tweeted last week that US Immigration and Customs Enforcement said it would suspend operations through the weekend in areas hit by Tropical Storm Barry, which weakened to a tropical depression Sunday.

Immigrant rights advocates across the United States, however, told CNN they saw few signs over the weekend of the ICE raids.

The agency Cuccinelli leads, USCIS, is tasked with overseeing legal immigration to the United States, including processing citizenship applications, providing immigrant employment authorization and administering humanitarian programs.

ICE, another agency in the Department of Homeland Security, deals with the detention and deportation of undocumented immigrants.

Cuccinelli is a longtime immigration hardliner, and since stepping into the acting role leading USCIS last month, he has frequently spoken publicly about the administration's efforts to crack down on illegal immigration.