The UN special envoy Martti Ahtisaari has said he doubts a negotiated settlement for Kosovo is possible.
A settlement for Kosovo's future remains elusive
He said the ethnic Albanian majority and the Serbs remained diametrically opposed on the final status issue.
In international law, Kosovo remains a province of Serbia, but has been administered by the United Nations since Serb forces were ousted in 1999.
"I don't see the parties moving on the status issue," Mr Ahtisaari told a parliamentary seminar in Helsinki.
However, he said there had been progress on technical matters since direct talks began in Vienna in February. He has been overseeing the talks.
Pressure on Ahtisaari
Last month the Serbian parliament adopted a new constitution declaring Kosovo to be an integral part of Serbia, despite the ethnic Albanians' demand for independence.
Serbia will now put the constitution to a referendum vote at the end of this month, to be followed by elections.
Failure to come to an agreement puts the onus on Mr Ahtisaari to come up with recommendations to be approved by the UN Security Council, the BBC's Balkans expert Gabriel Partos says.
There is widespread expectation that the eventual settlement will give Kosovo independence - albeit of a conditional kind, under strict international supervision to protect the Serb minority.
Because of this, the Serbian government would like to put off the decision on Kosovo's future, Gabriel Partos says.
But Mr Ahtisaari said he had received no instructions for a slow-down from the six-nation Contact Group spearheading the UN's efforts to find a settlement.
Contact Group diplomats have told the BBC any discussion about a revised timetable would be purely hypothetical at this stage.
But they say if, and when, Serbia does set a date for elections, the Contact Group may reconsider the timing.