Petersen visited Janjevo near Pristina, which has a Croat, Albanian and Roma population.
He said the United Nations wanted Kosovo Serbs to participate in the talks on the final status of the province and that it was, therefore, important for them to vote in the parliamentary elections.
Petersen voiced concern that Serbs' interests would not be taken into account in future discussions unless they took part in political processes and voted in the ballot.
He voiced readiness to hold talks with Belgrade to see if Belgrade's concept of the decentralisation of Kosovo could complement Pristina's existing plan on decentralisation and local government.