A week-old strike by more than 30,000 Los Angeles teachers that has disrupted classes for nearly half a million students neared an end on Tuesday as the teachers' union and the second-largest U.S. school district reached a contract deal.

"I'm proud to announce, pending approval, that we have an agreement that will allow teachers to go back to work on their campuses tomorrow," Mayor Eric Garcetti, who has mediated the talks, said at a news conference. He was joined by Alex Caputo-Pearl, the president of the United Teachers Los Angeles union, and Austin Beutner, the superintendent of the Los Angeles Unified School District.

Precise terms of the deal were not immediately disclosed.

Teachers walked off the job on Jan. 14 in their first strike in three decades against school district, demanding higher pay, smaller class sizes and the hiring of more support staff, such as nurses and guidance counselors.

The union also sought restrictions on the steady expansion of independently managed charter schools, arguing they divert resources from traditional classroom instruction for the bulk of the district's students.