FACTBOX-Major disputes between Russia and Ukraine

Jan 3 (Reuters) - A war of words between Moscow and Kiev over a gas supply cut escalated on Saturday, but energy is not the only issue the two ex-Soviet neighbours have argued about since Ukraine's 2004 "Orange Revolution" that incensed Russia.

NATO

Ukraine's President Viktor Yushchenko, swept to power by the revolution, has made joining the Western military alliance the cornerstone of his foreign policy, to the indignation of Russia which sees NATO's encroachment as a threat to its security.

Although most Ukrainians do not want to join NATO, Yushchenko has pushed on with the idea and requested from the alliance a Membership Action Plan. NATO has so far refused to give Ukraine the MAP but assured it that it would join one day. Ukraine backed fellow ex-Soviet Georgia, also a NATO aspirant, when Russia fought a brief war there in August.

CRIMEA AND THE BLACK SEA FLEET

The Crimean peninsula on the Black Sea was given to the Ukrainian Soviet Republic in 1954 by Moscow when it was inconceivable that Ukraine could be independent. It had been part of Russia for about 150 years.

A Russian fleet has been stationed there at Sevastopol for 225 years. It now remains under a lease agreement due to run out in 2017. Russia wants it extended, Ukraine said it would not.

Yushchenko was upset Russia could use the fleet against Georgia in August.