The issue has been raised at the highest level by Secretary of State John Kerry with his Russian counterpart, the State Department Spokesman John Kirby told reporters at his daily news conference.
“Secretary Kerry has raised our concerns about an incident involving an accredited US diplomat that occurred outside our embassy in Moscow,” Kirby said.
The call between Kerry and his Russian counterpart took place on Thursday, he said.
A video on Russian television station NTV is in circulation in this regard.