General Mark Milley, the chairman of the US Joint Chiefs of Staff, and his Russian counterpart, General Valery Gerasimov, met in Bern, a spokeswoman for Milley said.

They discussed "Syria, strategic stability and a variety of other operational and strategic issues to enhance deconfliction, improve understanding and reduce risk," Colonel DeDe Halfhill said.

"Both leaders recognize the importance of maintaining regular communication to avoid miscalculation and to promote transparency," she said.

The Russian defense ministry issued a virtually identical statement, adding: "The meeting was constructive."

It was Gerasimov's first meeting with Milley, who became chairman in September. The two men have spoken by phone but never before in person.

Milley's predecessor, General Joe Dunford, met several times with Gerasimov, who is chief of the Russian general staff, most recently in March in Vienna.

Despite the conflict in Syria and tensions between their two countries, the US and Russian military have kept open a permanent channel of communication between their leaders.