Updated

Mexico is pledging to spend $4.3 million to clean the Tijuana river channel after two California cities sued a U.S. agency over the decades-old problem of sewage fouling U.S. wetlands and beaches.

Mexico's National Water Commission said Monday it will strengthen and clean overflow channels and drains, to prevent sewage and garbage from flowing into the Pacific near the U.S. border. It also will renovate pumping stations and electrical components to carry the runoff to treatment plants.

The California cities of Imperial Beach and Chula Vista and the Port of San Diego contend the International Boundary and Water Commission's U.S. section failed to comply with the federal Clean Water Act.

Pollution forced the closure of beaches in parts of Imperial Beach on more than 160 days the past two years.