Croatia and Hungary recognized Kosovo as an independent country Wednesday and Bulgaria said it would establish diplomatic ties with Pristina on Thursday, drawing immediate denouncements from neighboring Serbia.
Kosovo's ethnic Albanian leadership had declared independence from Serbia on Feb. 17, despite fierce opposition from Serbia, Belgrade ally Russia and Kosovo's minority Serbs.
The U.S. and major European nations led the way in recognizing the new state soon after Pristina's declaration, prompting protests by Serbs in Serbia and Kosovo. Croatia's move could have even more serious implications in the Balkans.
Croatia and Serbia have a history of conflicts, and animosity still lingers following their 1991-95 war.
Serbian President Boris Tadic said earlier this week such a move would have "immediate negative" consequences on bilateral relations.
"Every country that decides to recognize the illegally declared state of Kosovo breaches international law" and so "can't count on good relations with Serbia," Serbian Foreign Minister Vuk Jeremic said in Athens, Greece.
As it has done with other countries that recognized Kosovo, Serbia immediately recalled its ambassadors to Croatia and Hungary.
Croatian Prime Minister Ivo Sanader told reporters that his country understands that the Kosovo issue is a "tough problem" for Serbia, but expressed hope that Zagreb's decision "will change nothing" in their relations.
Croatia obviously sought to side with Washington and the EU powers: the country hopes to join the EU by 2010, and also is expected to be invited next month to join NATO. U.S. President George W. Bush is coming to visit in two weeks.
The main opposition party and President Stipe Mesic defended the government's move. Mesic said Croatia "had to confirm a new reality" in Kosovo — the same it had expected from the world when the country declared its independence in 1991.
However, the decision could also affect Sanader's rule: his deputy, an ethnic Serb, voted against recognizing Kosovo and has offered his resignation.
Sanader immediately rejected it, but Slobodan Uzelac's party — which guarantees the coalition's majority in Parliament — has said it will consider pulling out of the government.
Relations between Croatia and Serbia have improved since Belgrade backed minority Serbs in Croatia who opposed Croatia's independence from the Yugoslav federation in 1991. Its move to recognize Kosovo could re-ignite old enmity.
Hungary's recognition of Kosovo also brings some risks: it has a 280,000-strong minority living in Serbia's northern province.
Foreign Ministry State Secretary Marta Fekszi Horvath said the country did not expect them to be affected by Kosovo recognition.
"We think it is not in the interests of the Serbian government for the Hungarians in Vojvodina to suffer atrocities," Horvath said.
In announcing their intention to recognize Kosovo, Croatia, Bulgaria and Hungary said in a joint statement that Kosovo should "provide guarantees for a multiethnic state" — namely its minority Serbs. They also supported Serbia's eventual accession to the EU.