Ukraine's Parliament on Tuesday decided to abandon the country's non-aligned status in favour of building closer ties with NATO.

The bill, passed in a 303-8 vote, marks departure from the non-aligned status, which Ukraine adopted under strong Russian pressure in 2010.

"Ukraine's fight for its independence, territorial integrity and sovereignty has turned into a decisive factor in our relations with the world," Poroshenko told foreign ambassadors in Kiev on Monday night.

Russian Prime Minister Dmitry Medvedev warned in a Facebook post on Monday: "In essence, an application for NATO membership will turn Ukraine into a potential military opponent for Russia." 

Moscow had set Kiev's non-participation in military alliances as a condition for any deal on helping end the conflict in eastern Ukraine pitting Kiev government forces against pro-Russian rebels.

Ukraine’s decision will deteriorate the relations even further, Russia's ambassador to the Organization for Security and Cooperation in Europe (OSCE), Andrey Kelin, said on Tuesday.

The government in Kiev has accused Russia of supporting the rebels – a charge dismissed by Moscow.

President Petro Poroshenko, who submitted the bill to Ukraine’s Parliament last week, said the refusal to join NATO in 2010 was the “biggest mistake of the former Ukrainian leadership.”

While NATO Secretary General Jens Stoltenberg has said countries that meet the criteria for becoming NATO allies may seek membership, Germany's Foreign Minister Frank-Walter Steinmeier has opined that it was possible for NATO to have a partnership deal with Ukraine, but not membership.

"Our door is open and Ukraine will become a member of NATO if it so requests and fulfils the standards and adheres to the necessary principles," a NATO spokesman in Brussels said on Tuesday, according to Reuters.