SOFIA, Jan 21 (Reuters) - Bulgaria decides on its defence plans in coordination with its allies in the North Atlantic Treaty Organization, Prime Minister Kiril Petkov said on Friday after Russia said its security demands included that NATO forces leave Bulgaria and Romania. Concern is running high in the West as Russia has amassed tens of thousands of troops near Ukraine"s border. Russia denies planning an attack, but says it could take unspecified military action if its security demands are not met. read more It wants NATO to promise not to admit Ukraine as a member and has urged the Western military alliance to halt eastward expansion. NATO has rejected the demands. "Bulgaria is a sovereign country, which has made its choice long ago by becoming a NATO member. As such, we alone decide to organise the defence of our country in coordination with our partners," Petkov told parliament. He said the North Atlantic Treaty did not provide for a lower category of members for which collective defence should be applied selectively or to a limited extent. Moscow has demanded legally binding guarantees that NATO will stop its expansion and return to its 1997 borders. Bulgaria, one of Moscow"s closest allies during the Cold War era, joined NATO in 2004. Russia and the United States could hold another meeting next month to discuss Moscow"s demands for security guarantees, Russia"s RIA news agency quoted a source in the Russian delegation as saying after talks in Geneva on Friday.