WASHINGTON — Nationwide immigration raids that were postponed three weeks ago are now scheduled to begin Sunday, two senior Department of Homeland Security officials told NBC News.

The mass raids, to be conducted by Immigration and Customs Enforcement, are set to target roughly 2,000 families in major cities across the United States — the same 10 cities that were revealed under the previous plans, the officials said. The previously named cities were: Atlanta, Baltimore, Chicago, Denver, Houston, Los Angeles, Miami, New Orleans, New York and San Francisco, but a source said that two of those cities may change.

The new timeline of the operation was first reported by The New York Times.

President Donald Trump tweeted last month that ICE would soon deport "millions" of undocumented immigrants living in the country. He then announced that the operation would be delayed "at the request of the Democrats."

Trump claimed on Twitter that he approved the delay so that Democrats and Republicans in Congress could work out a compromise on immigration policy — a deal that has so far eluded the president and his allies. Trump said the deal would have to solve “the Asylum and Loophole problems at the Southern Border.” Officials said the delay was due in part because details of the plan had leaked to the media.