Putin's visit to Belgrade is of political importance and should answer the question: is Serbia ready to be Moscow's key ally in the region, B92 portal reports, quoting Russian daily Kommersant.

If not, Serbia will continue its rapprochement with the EU and NATO, balancing between the West and Russia, assesses the Moscow daily.

The daily says that Serbian President Aleksandar Vucic has been actively pushing the idea of demarcation with Pristina lately, as a condition for normalizing relations, without which the integration of Serbia into the EU is impossible.

"Moscow is sceptical of the agreement between Serbia and Kosovo, which the EU wants, fearing that they would become a protectorate of NATO. In Moscow, they do not hurry to support the idea of a new demarcation, believing that Belgrade will recognize Kosovo. So, after today's talks on Kosovo problem, their interpretation can be completely different, as it was after the October meeting in Moscow," the daily write.

Disagreements between Moscow and Belgrade exist and about another principled issue, the daily said, and that is the humanitarian center in Nis.

Moscow's dissatisfaction was provoked and by the fact that Serbia, which Moscow considered "a key ally in the Balkans," has undertaken in recent years a series of steps towards NATO, Kommersant added, reports B92.