The U.S. State Department has given Canada the green light to potentially purchase 26 M142 High Mobility Artillery Rocket Systems (HIMARS) and related equipment for an estimated cost of $2.4 billion, the Pentagon said on Wednesday.

The approval by the U.S. Defense Security Cooperation Agency is the first major hurdle in the process for the Canadian Army to acquire the Lockheed Martin-built system, which gained a lot of public attention a few years ago as Ukraine sought to get its own rocket-propelled artillery to defend against the Russian invasion.

The deal still requires congressional approval and for the Canadian government to sign a deal with Washington, which will negotiate a contract with the manufacturer — something that is not expected until next year. U.S. lawmakers have 15 days to object to the sale after being notified by the defence agency. If they don’t, the sale is considered rubber-stamped.

In addition to the vehicles, the Pentagon says, Canada is looking to buy rocket launch pods for both operations and training.

“This proposed sale will support the foreign policy and national security objectives of the United States by helping to improve the military capability of Canada, a North Atlantic Treaty Organization (NATO) ally that is an important force for ensuring political stability and economic progress and is a contributor to military, peacekeeping and humanitarian operations around the world.” the defence agency statement said.

“This capability will protect Canada by improving Canada’s contribution to collective hemispheric defence and to defence and deterrence in Europe, as directed by NATO’s defence plans.”

U.S. government contractor technical, engineering and logistics personnel services are included in the deal, which will likely create a further political headache for the Liberal government of Prime Minister Mark Carney.

During last spring’s election, the Liberals pledged to diversify where Canada buys its military equipment.

The HIMARS is just one in a long list of U.S. military gear that’s either on order or about to be delivered. The F-35 stealth fighter, also built by Lockheed Martin, is the most high-profile example.