The Pentagon is planning to bring Ukrainian troops into the United States for training on the Patriot missile defense system, U.S. officials said Tuesday, signaling the Biden administration's latest test of Russian President Vladimir Putin's threshold for Western intervention in the conflict.

The training will occur at Fort Sill, an expansive facility covering roughly 145 square miles southwest of Oklahoma City, and could begin as soon as next week. The base is home to the U.S. military's basic Patriot missile defense training program and another curriculum designed to teach American personnel field artillery maneuvers.

The move follows President Biden's decision last month approving the transfer of a Patriot system to Ukraine, which for weeks has endured blistering Russian missile attacks on its energy grid and other vital infrastructure. Germany last week announced that it, too, would send a Patriot battery to bolster Ukraine's air defenses as millions face repeated blackouts that have cut heat, light and internet access for large portions of the country.

A Pentagon spokesman, Brig. Gen. Patrick Ryder, told reporters on Tuesday that the training will prepare about 90 to 100 Ukrainian soldiers to "operate, maintain and sustain" the defensive system through instruction that will take "several months." That's the same number required to operate a Patriot battery, which typically includes eight launchers each capable of carrying between four and 16 ready-to-fire missiles, depending on the type of munition.

American troops typically receive about a year of training on the Patriot before using it in the field. The Pentagon is looking for ways to compress that timeline for Ukrainian forces, given the urgent need to get them schooled up and sent back home.

"We certainly don't want to do anything that would jeopardize their ability to continue to fight," Ryder said. "But ultimately, that's a decision for the Ukrainians to make, in terms of how many troops they can afford to have come off the line in order to do the training."

Relying on Fort Sill, where a school already is established, will help the United States "expedite" the training under the instruction of U.S. Army personnel, Ryder said. Working separately from U.S. students, Ukrainian soldiers will receive instruction in classrooms, on the Patriot system itself, and in a simulation lab, he said.

The Pentagon has no other plans to bring Ukrainian forces to the United States for training on additional weapons systems, Ryder added, though he would not rule out that possibility should a future need arise. The administration, he said, is remaining "flexible."

Putin has seethed at NATO nations' involvement in the war, calling efforts by the United States and its allies to train and arm Ukraine acts of complicity. He has warned repeatedly that, if Russia feels threatened by outside forces, it won't hesitate to retaliate. For its part, the Kremlin has turned to fellow U.S. adversaries, Iran and North Korea, for help replenishing its weapons stocks as Western sanctions have strained its defense industry.

First used in combat during the Gulf War to take out Iraqi Scud missiles, the Patriot system relies on a sophisticated radar to find incoming threats, including cruise and ballistic missiles, and launches long-range missiles to intercept them. Typically deployed on the back of a truck, it requires a crew of at least three soldiers to operate, with extensive backup needed to keep it functional.

The plan to conduct the training at Fort Sill, first reported by CNN, comes as the Biden administration makes a series of moves to transform the Ukrainian military from a force primarily capable of halting the Russian advance into one that can mount more successful offensive operations intended to reclaim occupied Ukrainian territory.

Senior U.S. officials have said the Pentagon also is preparing to train hundreds of Ukrainian soldiers at a time at an American facility in Germany, focusing them on what the U.S. military calls combined-arms warfare. The concept integrates ground operations with long-range artillery, aviation and other weapons.

Biden in recent weeks also has approved a broad expansion of weapons transfers to Ukraine, with the United States agreeing to send heavily armored Bradley fighting vehicles, self-propelled artillery and thousands of rounds of ammunition to support them. It's an effort, Cooper said last week, intended to "change the dynamic" on the battlefield and enable Ukrainian forces to make greater progress along the war's front lines, which have stayed mostly static for months.

The package approved Friday included more than $3 billion in military assistance, the single largest transfer since Russia invaded Ukraine in February. The United States has approved the transfer of $24.2 billion in weapons since the invasion.