Football officials took issue with images from the Serbian team's dressing room in Qatar
The Football Federation of Kosovo (FFK) has called on FIFA to take action after accusing Serbia of an "aggressive" act with the display of a flag at the World Cup in Qatar.
Images circulating on social media showed the flag hanging in the Serbian team's locker room prior to their opening World Cup match against Brazil on Thursday.
The banner showed a version of the Serbian flag with a map of the country including Kosovo as part of it. The slogan "there will be no surrender" was written on the banner.
The FFK published a demand to FIFA on its website on Friday, railing against what it described as a "chauvinist act."
"It is unacceptable that this act is passed over in silence and we insistently demand that FIFA strictly apply its rules and punish the Serbian Football Federation for this aggressive act contrary to the values that football transmits," the message added.
Kosovo is a province of Serbia which was occupied by NATO after its 1999 bombing campaign. Its ethnic Albanian provisional government declared independence with US backing in 2008.
While the EU has urged Belgrade to recognize Kosovo's independence, Serbia has vehemently declined to do so. Russia is among the countries which do not recognize the region as a separate state.
Kosovo became a FIFA member in 2016, and political rows involving the region and Serbia have spilled over into football in the past.
Swiss players Granit Xhaka and Xherdan Shaqiri - both of whom are ethnic Albanians - were fined by FIFA after making the 'double-headed eagle' salute during a World Cup match against Serbia in Russia four years ago.
The gesture was seen as a reference to the eagle on the Albanian flag.
The current row comes amid tensions between Serbia and its breakaway province over the license plates used by vehicles.
A UN-brokered deal was reached in Brussels earlier this week, under which Serbia is expected to stop issuing 'KM' license plates for Kosovo cities, while Pristina has vowed to stop persecuting Kosovo Serbs who have Serbian-issued license plates.
On the pitch in Qatar, Serbia will be hoping to pick up a first win at the 2022 World Cup when they play Cameroon on Monday.
Following that is another potentially heated match with Shaqiri, Xhaka and Switzerland on Friday.
Serbia lost their opening Group G game 2-0 against Brazil, after a second-half double from forward Richarlison.