The United States has informed allies that it believes Iran has transferred short-range ballistic missiles to Russia for its war in Ukraine, according to two people familiar with the matter.

They did not offer any details about how many weapons have been delivered or when the transfers may have occurred, but they confirmed the U.S. intelligence finding. They spoke on condition of anonymity to discuss a matter that has not been publicly disclosed.

The White House declined to confirm the weapons transfer but reiterated its concern that Iran is deepening its support of Russia. The White House has been warning Iran for months not to transfer ballistic missiles to Russia.