Bosnian Serbs have been given a week to call off a referendum many fear will throw an already volatile country into further turmoil, Turkey's ambassador said Thursday.

Vefahan Ocak told The Associated Press Thursday that key world power ambassadors were informed of the deadline — which came into force Wednesday — by Bosnia's international administrator during a Sarajevo meeting aimed at resolving the standoff.

It's "an opportunity for meditation," he said.

Bosnian Serb leader Milorad Dodik wants to hold a mid-June vote to reflect what he says is a widespread rejection of Bosnia's federal institutions, especially the war crimes court. He has accused the court of bias.

The international administrator, Valentin Inzko, can annul or impose laws or even fire local politicians, including presidents. He has said that Dodik's referendum has the potential to jeopardize the entire 1995 peace agreement.

Inzko spoke to Dodik on Wednesday, but the Bosnian Serb leader remained adamant about the vote.

Bosnia is divided into two ethnic ministates — one for Serbs, the other shared by Bosniaks and Croats. The Serbs want to maintain as much autonomy as possible while the international community and the Bosniaks are pushing for more central institutions and the country to fulfill conditions to join the European Union.

Dodik has said repeatedly that the Serbs would rather drop the idea of Bosnia joining the EU if it requires them to transfer more power from their regional government to federal institutions. The referendum has led to a surge in his popularity.

He has previously threatened to hold a referendum on outright autonomy.

Oleg Milisic, a spokesman for the international administrator, said Inzko will next week inform the U.N. Security Council about what he termed the "worst crisis" to hit Bosnia since the end of the 1992-95 war.

Political analyst Tanja Topic said the Bosnian Serb leadership cannot now back off from the referendum without losing face. They "have pushed themselves into a corner," she said. "And any other decision but to hold the referendum would now be their political capitulation."

Independent think-tank the International Crisis Group told The Associated Press that the EU and the United States should not try stop the referendum because they don't have the power to physically prevent it. Besides, the results are nonbinding, ICG analyst Srecko Latal said. "Legally, they have the strength of a simple opinion poll."

International officials should ignore the referendum, he recommends, and the turnout will be low.

Bosnian Serb leaders have called for the vote as they claim the federal court and prosecutor's office are biased against them. They say most people imprisoned for war crimes are Serbs.

Dodik enjoyed the support of the West after the war, when he represented an alternative to Serb hard-liners inspired by former Serbian autocrat Slobodan Milosevic. However, after coming to power, his moderate rhetoric became increasingly nationalist. He has been re-elected twice on a nationalist platform.

In 2009, investigators opened a probe into allegations that he and his aides engaged in abuse of power, widespread fraud and embezzlement of millions of Euros

Many now believe he has personal reasons to go after the war crimes court and the office, as both have departments that deal with corruption.

Azhar Kalamujic, the editor of the Center for Investigative Journalism — which has carried out extensive research into Dodik's financial dealings — says Dodik's motives for the vote are clear: It's a smokescreen to stop the probes into his business dealings.

He says his attack on the court is just a widespread populist ploy to get other Serbs on his side, when all he's interested in is getting rid of the prosecutor's office to stop the probe.

All week, media have speculated on what steps each side could take, but they are unified in one outcome — If Inzko bans the referendum, Serb officials could withdraw from federal institutions and the country could grind to a halt.