Sessions, under Trump's orders, began a campaign against "sanctuary" policies that sheltered or protected undocumented immigrants from being deported.
"So here's my message to Mayor Schaaf: How dare you, how dare you needlessly endanger the lives of our law enforcement officers to promote a radical open borders agenda?" he said. Sessions said at a news conference.
Several Democratic elected officials joined demonstrators and spoke to the crowd with a bullhorn.
Watch more of Sessions' remarks below.
A line of police and private security guards blocked access to the hotel.
Sessions did not preview what his announcement will entail.
Late Tuesday, the US Justice Department (DOJ) sued California, upping the battle between The Trump Administration and state/local governments over the issue of providing sanctuaries from a crackdown on immigration enforcement.
Sessions said laws that limit information sharing essentially force ICE officers into more risky operations where they have to confront those they're seeking in the community where they could have greater access to weapons.
Sessions suggested California was trying to nullify federal law.
United Airlines flight experiences extreme turbulence, 'entire flight threw up'
According to Air Wisconsin's website, the aircraft was a Bombardier CRJ200 with a passenger capacity of 50 and a crew of three. High winds near Washington DC have made for such a rough landing that everyone on a recently-landing plane threw up.
On the eve of Attorney General Jeff Sessions' visit to Sacramento, Calif. on Wednesday, the Justice Department filed a lawsuit against California, the state's governor Jerry Brown, and the state's attorney general Xavier Becerra.
"Despite how (De León) has presented the issue, the law enforcement profession, which CPOA represents, can not and does not engage in immigration enforcement". Brown wouldn't comment on that. "Jeff Sessions just called me an embarrassment".
Sessions' lawsuit argues that the three laws passed by California past year violate the Supremacy Clause of the Constitution, which dictates that the federal government sets immigration policy.
Sessions strongly criticized Oakland Mayor Libby Schaaf for her recent unusual public warning that an operation by federal immigration officers was imminent. It claims that "information obtained or developed as a result of an agreement with a detention facility are federal records under the control of ICE. and are subject to disclosure only pursuant to applicable federal information laws, regulations, and policies".
In a statement a year ago the association's president, Gardena Police Chief Ed Madrano, said the compromise "addresses the significant public safety concerns we raised during this debate, and it reaffirms what we have held since the beginning, which is that California law enforcement should not be used to assist in mass deportations".
A federal judge on Monday rejected a request from the state of California to put a halt to the Trump administration policy of penalizing sanctuary city and state measures aimed at protecting illegal immigrants. The protesters are chanting "stand up, fight back" and "no justice no peace". There was a heavy presence of police on horses and bicycles and a helicopter overhead.
Like heads of other sanctuary city jurisdictions, the California leaders being sued by the Justice Department believe the federal government can't compel state and local police to enforce federal law, and that openness over immigration status encourages the undocumented to work with police and report other crimes, creating a safer environment.
The Justice Department disclosed the numbers in a lawsuit filed Tuesday against the State of California. Some legal observers believe the administration chose to file the case in the state's Eastern District, based in Sacramento, in part to avoid the more liberal judges in the Northern District, based in San Francisco.