U.S. immigration officials are preparing for a major sweep in San Francisco and other northern California cities to arrest more than 1,500 illegal immigrants, the San Francisco Chronicle reported.

According to the news outlet, the Immigration and Customs Enforcement operation aims to send a message that immigration policy will be enforced in the sanctuary state.

The sweep, centered in the Bay Area, could happen within weeks, and is expected to become the biggest enforcement action of its kind under President Donald Trump, the Chronicle reported, citing an unnamed source.

The operation would go after people who've been identified as targets for deportation, including those who have been served with final deportation orders and those with criminal histories, the Chronicle reported.

But officers could also scoop up other illegal immigrants in what are known as collateral arrests, the Chronicle reported.

The plan calls for immigration officers to be flown in from other parts of the country to help carry out the operation, the Chronicle reported.

The sweep would represent the first large-scale effort to target the region since Gov. Jerry Brown in October signed legislation enacting statewide sanctuary laws.