Boeing has been awarded a $416 million contract modification to produce three additional P8-A Poseidon aircraft for the U.S. Navy, a Department of Defense press release said.

“The Boeing Co., Seattle, Washington, is being awarded a $416,438,385 modification to a previously awarded firm-fixed-price contract (N00019-14-C-0067) for the manufacture and delivery of three Lot 9 full-rate production P-8A multi-mission maritime aircraft for the Navy,” the Pentagon release said on Thursday, May 25.

Fiscal year 2018 Navy aircraft procurement awards for the full of $416,438,385 will be obligated at the time of the award, none of which expire at the end of the fiscal year in September.

The U.S. Naval Air Systems Command in Patuxent River, Maryland, is the contracting activity. The majority of the work will be completed in Seattle, Washington with additional work in Baltimore, Maryland and Cambridge, U.K. as well as in New York, Illinois and California and “various other locations” within the U.S. Work is expected to be complete in October 2020.

Developed for the U.S. Navy, the P-8 Poseidon is a modified Boeing 737-800ERX designed to conduct anti-submarine warfare, anti-surface warfare, and shipping interdiction, as well as providing early warning protection. It can carry torpedoes, depth charges, Harpoon anti-ship missiles, and other weapons and can drop and monitor sonobuoys.

In December, Boeing was awarded a $1.2 billion contract to produce 10 P8-As for the Navy and the United Kingdom.

The P-8 Poseidon is designed to operate alongside the Northrop Grumman MQ-4C Triton Broad Area Maritime Surveillance drone.

It is operated by the U.S. Navy, the Indian Navy, and the Royal Australian Air Force, and has been ordered for the Royal Norwegian Air Force. In April 2017, the U.S. State Department approved a proposed $1.46 billion sale of P8-A aircraft and support to New Zealand.

A Boeing representative said during the Singapore Air Show this year that the company anticipates additional demand from the Asia-Pacific, both as a replacement for the P-3 Orion and due to increasing interest in maritime domain awareness among the U.S. partners in the region.