The Pentagon is considering training the Ukrainian armed forces to operate the Patriot missile defense system at a military base in the United States, according to two Defense Department officials.

Since Russia’s February invasion, the Ukrainian armed forces have completed training on a host of different NATO-provided weapons systems, including the U.S.-made High Mobility Artillery Rocket System, in eastern Europe, Germany and the United Kingdom.But until this point, none of the training has been done in the United States.

It would make sense to do the training in the United States, most likely at Fort Sill, Oklahoma, where most of the instructors and complex simulators are located, one of the officials said. Conducting the training in Europe would be doable but presents more logistical difficulties, the official said.

The system, which includes several support vehicles carrying control stations, radars and generators, likely won’t make it to the battlefield for many months. The military won’t transfer it to Ukraine until the Ukrainians are fully trained on how to use it, a third DoD official said Wednesday.

It’s likely the military will move a Patriot out of storage in the United States to Ukraine, instead of pulling a battery from a deployed location such as the Middle East or Europe, the official said. The latter would likely be controversial, as the batteries are in high demand across the world — particularly in Saudi Arabia and other Middle Eastern countries where they are defending against Iranian drones and cruise missiles