"Serbs and Russians are brothers forever," reads a giant billboard in Moscow.
Journalist Ivana Stradner posted the photo, writing that the giant sign was placed in front of Rossiya Segodnya, the state media conglomerate.
She wrote on Twitter that Russia and Serbia have good relations.
A large number of Serbian volunteers are reported to be fighting alongside Russian forces in Ukraine.
The behavior of Serbian President Aleksandar Vučić, who does not hesitate to threaten war whenever he has the opportunity, has been in the center of attention of geopolitical experts during the last few days, who have criticized the West for "caressing" him.
A group of senior politicians in the West have recently called for tougher attitudes towards Serbia.