Brussels - The European Union was marking the 10th anniversary of closer relations with six former Soviet states on Monday, though the event was overshadowed by a territorial conflict between Armenia and Azerbaijan.

Conflicts in the EU

The two neighbouring countries have been engaged in a decades-long conflict over the disputed region of Nagorno-Karabakh and failed to agree on language proposed for the joint declaration marking the event, EU diplomats said on condition of anonymity.

As a result, EU foreign policy chief Federica Mogherini is expected to issue an individual statement.

The EU's so-called Eastern Partnership programme was launched in 2009 to support and encourage democratic reforms in Armenia, Azerbaijan, Belarus, Georgia, Moldova and Ukraine.

The project helped precipitate the separatist conflict in eastern Ukraine, which erupted shortly after Kiev signed an association deal with Brussels.

Ukraine and Georgia in particular are hoping to begin membership talks with the EU - a prospect EU capitals keep putting off.

"European perspective"

"We want to offer these countries a European perspective," German Foreign Minister Heiko Maas said ahead of Monday's talks with his counterparts from the EU and the six former Soviet states.

Specifically, he said this could involve projects aimed at boosting employment and education in the partner countries.

"Notwithstanding difficulties and problems that we still face in the region, our partnership has managed to bring forward our common work on trade, economic development, human rights, the role of civil society, visa liberalisation and on many other fields," Mogherini said.

The celebration culminates with a leaders' dinner on Monday hosted by European Council President Donald Tusk and a high-level conference on Tuesday with European Commission President Jean-Claude Juncker.

The row between Armenia and Azerbaijan hinges on wording about the right to self-determination, sought by Yerevan. Baku wanted the joint text to support territorial integrity instead, diplomats said on condition of anonymity.

 EU member states