The Port of Los Angeles has said an oil spill from a subsea pipeline off the coast of California will not impact containership operations at the US west coast port.

On Sunday, the US Coast Guard (USCG) said it was responding to an oil sheen approximately 6 km (four miles) off the coast in Southern California.

"While some vessels waiting to come into San Pedro Bay may need to be cleaned, Port of Los Angeles operations and arrivals have NOT been impacted," the port said on social media.