Serbia's Prime Minister Aleksandar Vucic says he is ready to attend ceremonies making 20 years since the Srebrenica massacre.
Nearly 8,000 Muslim men and boys were killed by Bosnian Serb forces at Srebrenica during the Bosnian war.
Mr Vucic said he was prepared to "bow his head" to the victims.
The prime minister is closely associated with Serbia's nationalist past, and the move is seen as an attempt to improve ties with Bosnia.
Serbia is currently bidding for European Union membership.
"As prime minister, I am ready to bow my head to show the stand we take towards the innocent victims of Srebrenica," said Mr Vucic.
He described Srebrenica as "hell", but stopped short of calling it genocide, as the UN has done.
But Srebrenica Mayor Camil Durakovic said Mr Vucic's statement was a "provocation".
"It would have been better if he had said that he did not want to come, because Serbia still neither recognises what happened in the past, nor the judgements confirming that a genocide took place in Srebrenica," he told the AFP news agency.
The massacre was the worst in Europe since World War Two. It came amid the bloody break-up of Yugoslavia into independent states.
Serbia backed Bosnian Serb forces fighting the Muslim-led Bosnian government during the conflict.
In July 1995, in what was supposed to have been a UN safe haven, Bosnian Serb forces took control of Srebrenica. They rounded up and killed the men and boys and buried them in mass graves.
Mr Vucic was once a member of the ultra-nationalist Serbian Radical Party, but now he sees himself as a pro-Western reformer.