The top U.S. military officer, Air Force Gen. Charles Quinton Brown, spoke by telephone with Russian Chief of Staff Valery Gerasimov last week, the U.S. military said Wednesday. It was the first time Brown spoke with his Russian counterpart.

“The leaders discussed a number of global and regional security issues, including the ongoing conflict in Ukraine,” a Brown spokesperson said in a statement.

The rare call took place on November 27, but “at the request of General Gerasimov, General Brown agreed not to proactively announce the call.” The appeal request was made by the Russian Defense Ministry, the spokesperson said.

Brown became America’s top general last year, and Gerasimov last spoke with Brown’s predecessor, Mark Milley.

Tensions have increased in recent weeks. Ukraine has fired US and British missiles at targets in Russia, despite warnings from Moscow that it would consider such action a major escalation.

Earlier this month, Russian President Vladimir Putin, in a televised address, said Moscow had struck a Ukrainian military facility with a new medium-range hypersonic ballistic missile known as “Oreshnik” (the hazel tree). and warned that others could follow.