Russia will not hesitate to bomb American Patriot missile batteries should they be deployed to Ukraine, the Kremlin said, warning that the systems would be treated as legitimate targets amid reports that Washington may soon approve shipments to Kiev.

Kremlin spokesman Dmitry Peskov issued the threat on Wednesday, not long after the Washington Post reported that the White House is preparing to send Patriots to Ukraine, which has repeatedly requested the advanced missile defense system since Russia invaded in February.

While Washington has previously rebuffed requests for longer-range arms over concerns that Ukrainian forces may use them for strikes deep inside Russian territory, US officials have gradually become less worried about escalating the conflict. Still, complications linked to logistics and training continue to pose problems for the Patriot deployment, as explained by Kelley Vlahos of the Quincy Institute:

Training on the Patriot takes about six months. In the US Army, a “line battery” of upwards of 90 soldiers are required for the ongoing control and command of the system, which gives you an idea of how complex it is. The cost for each system is around $1 billion, not including the missiles.

The Defense Department is still working out plans for how to train Ukrainian troops on the Patriot, according to the Post, which noted the missiles may not reach the battlefield until the summer of 2023. 

Officials did not offer a clear explanation for the apparent about-face on the Patriot missile, as the White House has argued for months that such weapons could prompt major retaliation by Moscow and drag the United States into direct conflict with another nuclear power. Last Friday, the Times reported that the Pentagon had granted “tacit endorsement” for Kiev to carry out attacks inside Russian territory, citing a US defense official who said “the fear of escalation has changed” since the beginning of the war. 

Russia’s embassy in Washington also reacted sharply to the reports of an upcoming Patriot deployment on Wednesday, warning that the move would be a “provocative step by the [US] administration” which risks “unpredictable consequences.”