Tokyo breaks from longstanding weapons-export restraints and looks to add dozens of interceptors to American stockpiles.

Japan said Friday it would provide Patriot missiles to the U.S., bolstering global stocks as Ukraine defends itself from a new wave of Russian missile attacks.

Tokyo is set to transfer dozens of the interceptor missiles, which are used to shoot down ballistic missiles and other aerial threats, from its own supplies, starting as early as the first quarter of 2024, according to a U.S. official.

Japan will consider exporting dozens of Patriot missiles this week in a move aimed to indirectly support Ukraine in its defense against Russia's full-scale invasion, the Washington Post reported on Dec. 19.

The Japanese government plans to update export guidelines as early as this Friday allowing the shipment of several dozen Patriot missiles to the United States to backfill Washington’s stockpiles. Although the updated export guidelines would not allow Patriot missiles to be sent directly to war-affected countries like Ukraine and Israel, the transfers would give the U.S. more leeway to continue to supply Ukraine with American-made air defense systems.

Tokyo has not yet provided a timeline, but a decision on the number of missiles is expected soon. Japan currently manufactures missiles for the Patriot under license from Raytheon.

Although the export guideline modifications will not mention Patriot missiles by name, the changes in policy come in response to a request made by the Biden administration, U.S. officials speaking on the condition of anonymity confirmed to the Washington Post.

President Joe Biden addressed the matter with Prime Minister Fumio Kishida at Camp David in August, during a groundbreaking trilateral summit with South Korea, and reiterated it once more at an economic summit in San Francisco last month.

As Russia continues to ramp up it onslaught of attacks against civilian infrastructure, Ukraine remains in desperate need of modern air defenses to thwart Russian airstrikes this winter. In October, President Zelensky warned that Russia will likely attempt to destroy Ukraine's energy infrastructure.

Ukraine has seen success with the Patriot missiles they have in their possession. Ukraine received its first Patriot systems in April 2023, and soon after proved their effectiveness by downing air-launched ballistic Kinzhal missiles, lauded by Moscow as "unstoppable hypersonic" weapons.