U.S. Labor Secretary Tom Perez will travel to San Francisco on Tuesday to meet with both sides in a dispute between shipping companies and dock workers that has led to a partial shutdown of ports along the U.S. West Coast, his spokeswoman said on Monday. President Barack Obama, who is on a golf vacation in California, asked Perez to come to the state to try to broker an agreement on a new contract between dock workers and the group representing shippers and terminal operators. Ports along the coast, which between them handle nearly half of all U.S. maritime trade and more than 70 percent of imports from Asia, have been experiencing severe delays since October. Perez’s spokeswoman, Xochitl Hinojosa, did not give additional details about the secretary’s schedule. U.S. officials have said previously that Perez will urge both sides to resolve their dispute quickly and at the bargaining table.