One diplomatic official told CNN that the Trump administration wants the meeting in Washington but Moscow has insisted on neutral ground. The official added that Vienna is the likely location.

No official announcements have been made.

Kremlin spokesperson Dmitry Peskov said Thursday that White House national security adviser John Bolton plans to visit Moscow. The timing of the visit wasn’t immediately clear.

In a conference call with reporters, Peskov said the Kremlin was aware of Bolton’s plans.