The largest containership to ever call at a U.S. port will arrive the day after Christmas, when an 18,000 20-foot container equivalent unit (TEU) ship operated by French liner CMA CGM reaches the Port of Los Angeles.

The ship, called "The Franklin," will then call at the Port of Oakland five days later, according to the Marseille-based CMA CGM, the world's third-largest liner company. The vessel will return to the U.S. in early 2016, when it calls at the Port of Long Beach, adjacent to Los Angeles, according to Los Angeles port officials.

The Franklin, the world's 10th-largest containership, was launched from a Chinese shipyard last month. CMA CGM said it will deploy the vessel on a regularly scheduled service between California, China, and South Korea. However, the liner company has not disclosed detailed sailing plans for the ship. CMA CGM has three other 18,000-TEU ships in its fleet.

Currently, the largest ships currently serving the U.S. carry 14,000 20-foot containers. Oakland regularly handles vessels that size. Vessels calling at Los Angeles, the nation's busiest seaport, max out at between 12,000 and 13,000 TEUs.

The Franklin's first visit to Oakland is considered a trial run to ensure that the vessel can be properly berthed and cargo efficiently discharged, port officials said in a statement yesterday. A Port of Los Angeles statement did not mention whether the call would be a trial run. Most U.S. ports lack the water depth for large vessels with such a deep draft.

Last week, CMA CGM announced plans to acquire Singapore-based Neptune Orient Lines, the parent of container liner APL, for $2.4 billion in cash. The proposed deal must be cleared by U.S., Chinese, and European Union antitrust authorities.