Greece's government, angered by a U.S. decision to recognize the name of neighboring Macedonia, said Friday it would block its Balkan neighbor from joining NATO or the European Union unless the name dispute is resolved.

Greece objects to the country's constitutional name, the Republic of Macedonia (search), because Athens says it implies territorial claims toward Greece, which has a territory called Macedonia.

The United States, however, announced Thursday that it was recognizing the name, bringing a sharp complaint from the Greek government.

Greece's warning Friday appeared aimed at preventing European nations from following the U.S. lead.

"It is well known that the accession of a European country to the EU or NATO (search) requires the unanimous agreement of all existing members," government spokesman Evangelos Antonaros said.

"Greece will not be part of such a decision unless a commonly acceptable solution [to the name dispute] is reached."

Macedonia, which won independence from Yugoslavia, joined the United Nations under the name "Former Yugoslav Republic of Macedonia," or FYRM, to sidestep Greek objections.

Greece, the European Union (search) and international organizations use the FYRM acronym to refer to Macedonia. The EU said Thursday it has no plans for now to change its policy on the name.

State Department spokesman Richard Boucher said Thursday that the U.S. decision to recognize Macedonia's name came in part to boost the government as it tries to defeat a referendum backed by the country's nationalists that would block a new decentralization law.

The law would give the Balkan country's ethnic Albanians more power. International officials back the law because it is in line with a 2001 Western-brokered peace deal that ended six months of fighting between government troops and ethnic Albanian rebels.