North Atlantic Treaty Organisation leaders discussed ties with Georgia at their summit in Brussels in July, a move Medvedev, who was president when Russian and Georgian forces clashed in 2008, condemned.
He added that "Russia's aggressive policy in the region, the lack of will to regulate the conflicts caused by the Kremlin, is a serious threat to post-war order in Europe and compliance with worldwide law".
"We can say that Georgia's integration with North Atlantic Treaty Organisation is the only guarantee for the security, stability and sustainable development of the region", Pkhaladze said.
A roundtable meeting on Russia-Georgia war is also scheduled to be held in Tbilisi on Tuesday with attendance of the same ministers.
He added that the European Union made a "big mistake" in letting it pass without outcome, adding that "we have to do everything to prevent this from happening again".
In a statement issued on Tuesday, the EU's foreign policy chief Federica Mogherini said the "Russian military presence in both Abkhazia and South Ossetia continues to violate worldwide law".
North Atlantic Treaty Organisation leaders discussed ties with Georgia at their summit in Brussels in July.
The foreign ministers of Poland, Lithuania and Latvia and the deputy prime minister of Ukraine were in Georgia on Monday and Tuesday on a visit marking 10 years since Russia's invasion of that country, public broadcaster Polish Radio's IAR news agency reported.
Eastern European countries, which were formerly in the Soviet Union's sphere of influence, have in recent years frequently campaigned in favour of the two countries' accession.
Under NATO rules, countries with territorial conflicts can not join the alliance.
NATO now supports Georgia through the Substantial NATO-Georgia Package, a set of initiatives that provides resources to strengthen Georgia's defenses.
Russian President Vladimir Putin, in turn, stated that Moscow would view NATO's further expansion, including the accession of Georgia and Ukraine, highly negatively, TASS is reporting. "We do not understand why it is necessary", Medvedev said.
Under NATO rules, countries with territorial conflicts can not join NATO.
"Moscow further enhances its illegal military presence on the ground and prevents the creation of worldwide security mechanisms in Georgia's Abkhazia and Tskhinvali regions", the statement added.