The Army Tactical Missile Systems (ATACMS), with a range up to 300 kilometers, were included in the $300-million package of military aid approved by President Joe Biden on March 12, according to the official, who spoke with Reuters.

Speaking on condition of anonymity, the source said that Ukraine used the missiles for the first time last Wednesday, targeting a Russian airfield about 165 kilometers (103 miles) from the front line.

On the morning of April 17, Ukrainian President Volodymyr Zelensky said his forces had attacked the airbase in Dzhankoy, Crimea. The Russian Defense Ministry has not commented on that claim.

Zelensky has long clamored for longer-range missiles. According to the anonymous official cited in Reuters’ report, the Pentagon was initially opposed, but changed its mind after Russia used ballistic missiles allegedly supplied by North Korea and began targeting Ukraine’s energy infrastructure.

“We warned Russia about those things,” the official said.

“They renewed their targeting.”

Biden was advised to send the longer-range missiles by National Security Advisor Jake Sullivan, Defense Secretary Lloyd Austin, Secretary of State Antony Blinken and Joint Chiefs of Staff Chairman Charles Q Brown, the official added.

The ATACMS were acquired from Lockheed Martin, rather than from the Pentagon stockpiles, and paid for by the “savings” discovered in March, when several military contracts were reportedly delivered for less than the original bid value.

According to the official, Biden instructed his aides to include the ATACMS in the package but to keep it secret, so as to preserve Ukraine’s “operational security and the element of surprise.”

Ukraine first received mid-range ATACMS last September. The Russian military quickly began shooting them down, however, thwarting Zelensky’s plan to damage or destroy the Crimean Bridge.

“This is yet another mistake on the part of the United States,” Russian President Vladimir Putin said last October, explaining that, had Washington refrained from sending the missiles, it could have later positioned itself as the “good guy” for its attempts to prevent needless casualties.

With Russia upgrading its air defenses to intercept the ATACMS, their arrival will not have a major impact on combat operations, and will only “prolong the agony” of Ukraine, Putin explained, adding, “That’s why it’s a mistake.”

Reacting to Washington’s secret delivery of ATACMS missiles to Kiev, Russian ambassador to Washington Anatoly Antonov said the long-range missiles that the US has supplied to Ukraine are “extremely dangerous weapons”, but they will not help Kiev turn the tide of the conflict against Moscow.

The delivery of long-range missiles to Kiev is “impossible to justify”, Antonov wrote in a post on Telegram on Thursday.

The move by Washington “increases the threat to the security of Crimea, including Sevastopol, the new Russian regions [the People’s Republics of Donetsk and Lugansk, and the Kherson and Zaporozhye Regions] and other Russian cities”, he added.

The assurances by the US officials that the long-range missiles will not be used against Russian territory are “particularly cynical,” the ambassador stressed.

“How can we ignore the numerous terrorist attacks by Kiev’s criminals? Deadly strikes on hospitals, schools, kindergartens, bridges and even their own servicemen?”

Antonov reminded that the Russian forces have already shot down mid-range ATACMS missiles, which Ukraine had received last September. The same will happen with their long-range counterparts, he assured, adding that “neither these missiles nor other weapons can help defeat Russia”.

“Aren’t local politicians [in the US] afraid of drowning in the quagmire of conflict? Washington will not be able to get out of the horrible swamp that has absorbed the blood of ordinary soldiers,” the envoy warned.

Russian Foreign Ministry spokeswoman Maria Zakharova pointed to the fact that Washington’s acknowledgement of the delivery of long-range ATACMS to Ukraine comes amid attempts by Kiev and its Western backers to “deceive the international community into some kind of conference on the ‘Zelensky formula’”.

“Washington’s plan is sickeningly simple: drag everyone into a pointless meeting under the pretext of ‘peaceful intentions’, while at the same time boosting Zelensky’s terrorist potential,” she wrote on Telegram.