Defense Secretary Lloyd J. Austin III spoke by phone on Tuesday with Russia’s new defense minister, Andrei Belousov, the Pentagon said, in a rare conversation between the Biden administration and Moscow.

This was the first phone call between the two men since Mr. Belousov, an economist, replaced Sergei K. Shoigu, Russia’s long-running defense minister, in a Kremlin shake-up in May.

Maj. Gen. Patrick S. Ryder, the Pentagon press secretary, said that Mr. Austin “emphasized the importance of maintaining lines of communication amid Russia’s ongoing war against Ukraine.”

Mr. Austin initiated Tuesday’s call and “believes that keeping lines of communication open are important,” General Ryder said.

The lack of communications between senior Russian military and defense officials and their American counterparts has fed fears at the Pentagon of miscalculation risks.