Montenegro and Macedonia on Thursday recognized Kosovo, a move which is certain to raise tensions between Serbia and its former sister republics, dpa reported.
Macedonian parliament after a marathon emergency session, voted with a vast majority to recognize Kosovo. The Macedonian government is due to confirm the decision later in the evening.
Montenegro's government unanimously reached its decision to acknowledge Kosovo, eight months after it unilaterally declared independence from Serbia. Serbia had earlier said the Montenegro's decision would be a "stab in the back."
Belgrade claims Kosovo as its province and has threatened diplomatic measures against all countries that recognize it. It has earlier pulled back its ambassadors from countries that nevertheless made the move. Officials also said harsher measures were being considered in the case of Kosovo's neighbours Montenegro and Macedonia.
Nearly 50 countries have recognized Kosovo, including the United States and 22 out of the 27 European Union nations. Kosovo's broad recognition was however blocked in the United Nations by Serbia's superpower ally Russia.
Hours after Montenegro recognized Kosovo, Belgrade declared its ambassador in Serbia a "persona non grata" and will most likely do the same with Macedonia's chief diplomat.
Serbia earlier adopted secretive "action plans" with measures against countries that establish ties with its breakaway province.
Montenegrin Foreign Minister Milan Rocen said the decision was synchronized with that in Macedonia. In Skopje, parliament adopted the resolution on Kosovo, stating that "Macedonia as a candidate for the membership in the EU and NATO needs to join the common stance and policy of those two organizations."
Both Montenegro and Macedonia were along with Serbia a part of the former Yugoslavia, which started falling apart in 1991. Macedonia left in 1993 and Montenegro was the last to leave Serbia, in 2006.
Both small countries, particularly Macedonia, with its fragile stability, and large, restive Albanian minority, came under strong Western pressure to recognize the new country in order to keep the door open for future integration with NATO and EU.
On Wednesday Serbia pushed through a decision in the United Nations General Assembly to seek an advisory legal opinion on Kosovo's independence from the International Court of Justice.