On his first visit abroad as Serbia's new president, Tomislav Nikolic reiterated his refusal to recognise Kosovo and sought "clarification" on EU-brokered talks between Belgrade and Pristina.

"I was assured the European Union will not demand from us to recognise Kosovo officially, but demanding from us to have better relationships," said Nikolic, referring to Kosovo's 2008 proclamation of independence.

Nikolic spoke after meeting EU president Herman Van Rompuy, European Commission president Jose Manuel Barroso and EU foreign policy chief Catherine Ashton on what was his maiden foray outside Serbia.

Though pressed by EU leaders to continue ground-breaking talks with Kosovo begun under the previous administration in Belgrade, Nikolic said he was seeking further clarification from EU mediator Robert Cooper.

"I will support all agreements that are not against the constitutional order of Serbia and are not harmful to the citizens of Serbia and I maintain this position," he said.

He said he believed "no harmful effect has been made so far" but needed answers on details from Cooper. "We have to have some clarifications about the critical points."

Both Barroso and Van Rompuy said better ties with Kosovo were key to Brussels opening membership negotiations with Belgrade after the country got a foot in the EU door last March by being granted official candidate status.

"Normalisation of Serbia's relations with Kosovo remains an absolutely central condition for moving to the next stage of the EU processs," said Barroso.

Nikolic came under fire shortly after taking office some two weeks ago when he declared that the 1995 Srebrenica massacre of 8,000 Muslim men and boys in Bosnia was not genocide.

A former hardline ultra-nationalist turned pro-European populist, he also angered Zagreb with statements about the 1991-95 war between Croatia and Belgrade-backed rebel Serbs.

All regional heads of state bar that of Montenegro boycotted a reception to mark his inauguration this week.

As Nikolic expressed hopes in Brussels of starting EU accession negotiations by year's end -- a process that requires a country to kick off key reforms -- the EU handed Kosovo a stringent list of almost 100 conditions to meet before Kosovans can travel to the EU's passport-free Schengen zone without a visa.

The citizens of Kosovo are the last in the Balkans to need visas to travel into the Schengen zone covering 26 countries without border controls between them.