WASHINGTON >> Earlier this month, Defense Secretary Lloyd J. Austin III received an unusual request from an unlikely caller: His Russian counterpart wanted to talk.

Since Russia invaded Ukraine in February 2022, Austin had spoken by phone with Russia’s defense minister only five other times, almost always at the Pentagon’s initiative and often in an effort to avoid miscalculations that could escalate the conflict.

In fact, Austin had reached out to Russia’s new defense minister, Andrei Belousov, just a couple of weeks earlier, on June 25, in an effort to keep the “lines of communication open,” the Pentagon said. It was the first phone call between the two men since Belousov, an economist, replaced Sergei K. Shoigu, Russia’s long-running defense minister, in a Kremlin shake-up in May.

Now, on July 12, Belousov was calling to relay a warning, according to two U.S. officials and another official briefed on the call: The Russians had detected a Ukrainian covert operation in the works against Russia that they believed had the Americans’ blessing. Was the Pentagon aware of the plot, Belousov asked Austin, and its potential to ratchet up tensions between Moscow and Washington?

Pentagon officials were surprised by the allegation and unaware of any such plot, the two U.S. officials said, speaking on the condition of anonymity to discuss the confidential phone call. But whatever Belousov revealed, all three officials said, it was taken seriously enough that the Americans contacted the Ukrainians and said, essentially, if you’re thinking about doing something like this, don’t.

Whether the alleged Ukrainian plot this month was real and imminent is still unclear, as is what form it might have taken. Pentagon and White House officials say nothing has happened — yet. They have declined to describe the call in detail but stressed the need for dialogue among adversaries.

A Russian Defense Ministry statement after the July 12 call confirmed that Belousov initiated it, adding that “the issue of preventing security threats and reducing the risk of possible escalation was discussed.” But the statement made no mention of a suspected Ukrainian covert mission.

Ukrainian officials declined to comment on the matter. The Kremlin also declined to comment for this article, and the Russian Defense Ministry did not respond to a request for comment.

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