Kosovo is 90 per cent ethnic Albanian, and declared independence from Serbia in 2008.
However, Serbs dominate in a small area of the north bordering Serbia and continue to function as part of the Serbian state, resisting efforts by the Kosovo government to extend its authority.
The row cost Serbia official candidate status for membership of the European Union last week.
The Russian convoy of some 25 trucks is carrying 300 tonnes of humanitarian aid for minority Serbs in Kosovo, Serbian media reported.
However, it was halted by EU customs officers late on Tuesday when it tried to enter Kosovo through a disputed border gate.
The gate is one of two crossings at the heart of the dispute, which started in July when Kosovo prime minister Hashim Thaci sent special police units to the northern border, only to see them repelled by armed Serbs.
Serbian roadblocks are preventing the EU’s police and justice mission in Kosovo from operating freely in the north, forcing the mission to use helicopters.