Washington, Sha'ban 10, 1436, May 28, 2015, SPA -- NATO Secretary General Jens Stoltenberg vowed Wednesday to uphold the territorial integrity of Europe as the military alliance faces a belligerent Russia on its eastern flank, according to dpa. "We will firmly uphold sovereignty and territorial integrity of all European countries," Stoltenberg told the Center for Strategic and International Studies in Washington. The alliance will work to ensure its neighbours, Georgia, Moldova and Ukraine, remain stable and independent, he said at the think tank, a day after discussing the conflict in Ukraine with US President Barack Obama. "These nations are not buffer zones, they are independent sovereign states," he said. "They have the right to choose their own paths and we will help them on that path." In a separate speech, US Vice President Joe Biden warned that Russian interference in the region could undermine the international world order by undercutting principles of security, territorial integrity and the inviolability of borders. "Russia is taking actions to weaken and undermine its European neighbours and reassert its hegemonic ambitions, and we need to be able to respond," Biden told the Brookings Institution. He called for US and European sanctions to remain in place until Moscow abides by the Minsk ceasefire agreement reached in February. Stoltenberg also warned Russia against interfering in its neighbours' aspirations to join NATO. "Whether another country is going to become a member of NATO or not is going to be decided by that country and 28 allies - no one else," he said. Georgia, which fought a brief war with Russia in 2008, hopes to join NATO despite Moscow's opposition. But the country still has much work ahead to bring its democratic process in line with its NATO's demands. Ukraine last year dropped its non-aligned status in what was seen as a major step toward a potential bid for NATO membership, but the alliance has played down expectations. --SPA 02:33 LOCAL TIME 23:33 GMT www.spa.gov.sa/w