Ukrainian Parliament, Rada, on 24 December 2014 overwhelmingly adopted a bill that enables the country to join North Atlantic Treaty Organisation (NATO). The bill was adopted by 303 to eight votes.
With this, Ukraine dropped the non-aligned status to join NATO. The non-aligned status was adopted by Ukraine in 2010 under Russian pressure. The status of non-aligned prevents states from joining any military alliances.
During his election campaign in early 2014, President Petro Poroshenko had vowed to put Ukraine under Western military protection.
Russia is strongly opposed to any eastward expansion of NATO. Earlier, in February 2008 Russian President Vladimir Putin had said Russia may target its missiles at Ukraine if its neighbour joins NATO and accepts the deployment of a US missile defence shield.
Russia has long complained about NATO expanding east, up to Russia's borders. Russia would view Ukraine's membership of the alliance as a direct threat to its national security.
But Moscow has been quick to denounce the Ukrainian parliament for renouncing the country's non-aligned status.
The move to join NATO would drive another wedge between Kiev and Moscow. The move may complicate efforts to resolve the current crisis.
The North Atlantic Treaty Organization (NATO) also called the North Atlantic Alliance is an intergovernmental military alliance based on the North Atlantic Treaty which was signed on 4 April 1949.
The organization constitutes a system of collective defence whereby its member states agree to mutual defence in response to an attack by any external party.
NATO's headquarters are in Brussels, Belgium, one of the 28 member states across North America and Europe. Albania and Croatia had joined NATO in April 2009.
When: 24 December 2014