FACTBOX: Turkey and Armenia move to overcome differences

(Reuters) - Armenia and Turkey moved closer to establishing diplomatic ties and reopening their border on Monday, saying they would sign accords within six weeks under a plan to end a century of hostility.

The neighbors have no diplomatic ties, a closed border and a history of animosity stemming from the mass killing of Armenians by Ottoman Turks during World War One. Turkey says there was killing on both sides and rejects charges of genocide.

Here are the key issues that have marred relations.

* NAGORNO-KARABAKH:

Turkey closed its land border with Armenia in 1993, in protest at Armenia's backing for Nagorno-Karabakh, a mountain region in Azerbaijan where ethnic Armenian separatists threw off rule from Baku in a war with the collapse of the Soviet Union.

Turkey has long linked improved ties with Armenia with progress on settling the fate of Nagorno-Karabakh, with Azeri and ethnic Armenian forces facing off over a tense frontline 15 years after agreeing a ceasefire.

Turkey and Azerbaijan share deep cultural, religious and linguistic ties.

* SOME HISTORY:

In the late 19th century the Armenian minority, numbering an estimated 2 million, in the Ottoman Empire were encouraged by exiled groups in the United States, Geneva and in the Georgian capital, Tbilisi, to assert their nationalism.

Repression by Ottoman irregulars, mainly Kurds, led to the massacre of some 30,000 Armenians in eastern Anatolia in 1894-1896. Several thousand more were killed in Constantinople in August 1896 after Armenian militants seized the Ottoman Bank. Massacres were stopped after the Great Powers threatened to intervene.

* WHAT HAPPENED IN 1915:

As the Ottomans fought Russian forces in eastern Anatolia during World War One, many Armenians formed partisan groups to assist the invading Russian armies.

On April 24, 1915, Turkey arrested and killed hundreds of Armenian intelligentsia.

In May 1915, Ottoman commanders began the mass deportation of Armenians from eastern Turkey thinking they might assist Russian invaders.

Thousands were marched from the Anatolian borders toward Syria and Mesopotamia (now Iraq) and Armenians say some 1.5 million died either in massacres or from starvation or deprivation as they were marched through the desert.

* DIFFERING VIEWS:

Ankara says large numbers of both Christian Armenians and Muslim Turks were killed during the violent and chaotic break-up of the Ottoman Empire. A law in Turkey makes it a criminal offence to call the killings a genocide.

Armenia insists the killings should be declared a genocide and the massacres have been recognized as such by some Western politicians.

Turkey also objects to Yerevan's claims on some of its land.

Sources: Reuters/Dictionary of Twentieth Century History.