(AP-ANSA) - SKOPJE - Thousands of people have gathered Saturday in 15 cities in Macedonia to celebrate an invitation that NATO recently extended to this Balkan nation to become the 30th member of the military alliance. NATO leaders formally invited Macedonia earlier this week to start membership talks, with the condition that membership can't be completed until the name deal with Greece is fully implemented. Macedonia signed a deal last month with Greece that will see its name changed to "North Macedonia." Dozens of musicians entertained people late Saturday in celebrations in Skopje and elsewhere that the left-wing government has organized to mark the decade-long aspiration. Macedonia's conservative opposition VMRO-DPMNE party has denounced the celebrations. It says "Macedonia does not need celebrations, but (a government) apology for capitulation" on the name issue. (AP-ANSA).