Bath Iron Works on Tuesday was awarded a Navy contract to build three more destroyers as the U.S. continues to expand the navy to counter China’s growing fleet.

Twelve destroyers are now in the works at BIW, which on Saturday christened its 40th Arleigh Burke-class destroyer.

BIW has delivered 38 such destroyers to the Navy, while Ingalls Shipbuilding in Mississippi said it has delivered 35. They are the only shipyards that build the vessels.

“Today’s award of three DDG-51s is a testament to Navy’s confidence in the hardworking and highly skilled men and women at BIW who have earned the reputation that ‘Bath built is best built,'” Maine’s congressional delegation said in a statement. “We are pleased that this contract will provide a stable foundation to the shipyard for at least the next five years and ensure our sailors — and country — have the ships they need to keep the nation safe. In addition, as BIW continues to work to deliver DDG-51s on time and increase productivity in the coming years, the contract includes the potential for additional ships and more work.”

The three destroyers will be Flight III models, which have Raytheon’s new SPY-6 radar, billed as the most advanced naval radar in the world.

“We appreciate the opportunity to build on our history of providing these highly advanced ships for the U.S. Navy fleet and are honored to do our part to contribute to protecting the nation and our families,” said BIW President Chuck Krugh in a statement. “Flight III destroyers have significantly increased capability, and our skilled shipbuilders are committed to producing ships that meet the quality standards that our Navy sailors deserve.”

U.S. Sens. Susan Collins and Angus King and Reps. Chellie Pingree and Jared Golden on Tuesday made a joint announcement about the contract, which includes a provision for five more destroyers.

Ingalls Shipbuilding on Tuesday was awarded a contract for six destroyers.

The destroyers, which cost about $2 billion apiece, are commonly called the backbone of the Navy’s fleet. They can simultaneously engage ships, submarines, aircraft and missiles.

The Maine delegation has said a larger naval fleet is a priority amid the ongoing war in Ukraine and concerns China could invade Taiwan. President Joe Biden has said the U.S. will protect Taiwan in such a scenario.

The Bath-built USS Thomas Hudner earlier this month was deployed to the Middle East as a deterrent after American military officials said Iran’s navy has been harassing shipping vessels in the Strait of Hormuz.

BIW is aiming to increase destroyer production to 1.5 ships a year. Krugh has said workers have been speeding up production recently after slowdowns that started in 2020 due to a combination of the coronavirus pandemic and a union strike. That union, Machinists Union Local S6, is the largest of the shipyard’s five unions and is currently negotiating a new contract.

Collins is vice chairperson of the Senate Appropriations Committee and ranking member of the Defense Appropriations Subcommittee, King is on the Senate Armed Services Committee, Pingree is on the House Appropriations Committee, and Golden is on the House Armed Services Committee. The armed services committees authorize military spending for destroyers, while the appropriations committees allocate money to build them.