EU-brokered talks between the prime ministers of Serbia and Kosovo - thought to be tackling the sensitive issue of the ethnic Serbian minority living in northern Kosovo - were due to resume the following day, sources said late Tuesday, DPA reported.
"Discussions are ongoing," said a spokeswoman for EU foreign policy chief Catherine Ashton, who held three-way talks with Serbian premier Ivica Dacic and Kosovo's Hashim Thaci after meeting each of them bilaterally.
But sources said they were not due to resume their joint meeting until Wednesday, after holding extensive discussions. The leaders were expected to consult in the meantime.
Sunday marked five years since Kosovo declared independence - a move that is not recognized by Belgrade.
Thaci said ahead of the talks that his country was committed to "normalizing relations with Serbia as two independent and sovereign states". This would lead to the "normalization of the entire region," he added.
Earlier Tuesday, EU President Herman Van Rompuy lauded the "good progress" made so far in the talks, and urged Thaci at a joint press conference to continue displaying "the same constructive approach."
It is the fifth round of talks under EU auspices, and follows a Brussels meeting earlier this month between the Serbian and Kosovan presidents - who rank higher but have less political clout than their premiers.
Brussels insists, as a condition for EU accession talks, that Belgrade must dissolve its parallel institutions that support the ethnic Serbs who form a majority in northern Kosovo.
But Serbia says it will only do so if its minority is given a broad degree of autonomy from Pristina.
Belgrade spends up to 300 million euros (400 million dollars) annually on local authorities, justice, education and health infrastructure in northern Kosovo - keeping the Pristina authorities at bay.
Serbia accepted the revival of talks with Kosovo, after the EU made it a condition for progress on Belgrade's bid for membership in the European bloc.
The talks are meant to remove obstacles to normal life stemming from Kosovo's secession. Previous rounds have so far achieved an agreement on the joint management of crossing points.