Donald Trump will not deploy federal agents to San Francisco, the U.S. president and the California city's mayor said in separate social media posts on Thursday, a surprising stand-down as Trump pressures Democratic-led cities around the country to step up enforcement against crime and illegal immigration.

City Lights Books, the North Beach landmark that helped define the Beat Generation, has revived founder Lawrence Ferlinghetti's 2007 poem "Pity the Nation."

Officials say Border Patrol's operations in the Northern California area could start as early as later this week, but that the timing could shift.