Brussels - European Union leaders were attempting Friday to balance their desire to deepen relations with six Eastern European nations with their need to not go up too strongly against Russia.

The summit will be the fifth time since 2009 that the EU is meeting with leaders from Armenia, Azerbaijan, Belarus, Georgia, Moldova and Ukraine - countries that have historically been subject to strong Russian influence - to draw them closer to Europe politically and economically.

Developing  relations with neighbours

The EU is trying to walk a fine line between deepening cooperation with countries in the so-called Eastern Partnership, while emphasizing that the framework is meant to be non-confrontational towards Russia, which might see these efforts as encroaching on its power over the region.

"This is not an enlargement summit, nor an accession summit," said European Commission President Jean-Claude Juncker.

"We are developing our relations with our important neighbours - they have to be consolidated."

Belarusian Foreign Minister Vladimir Makei, who was representing his country in the notable absence of President Alexander Lukashenko, said he wanted to be able to tell his countrymen what tangible results partnership with the EU could bring ordinary citizens.

"We would like to have this Eastern Partnership summit as a result-oriented summit, as a summit which will bring concrete dividends, concrete benefits for our people," Makei said.

He said his country was "between two big fires" - namely Russia and the EU.

"They are today rivals, unfortunately," Makei said. "But we would like to get away from this confrontation rhetoric."

Shared challenges in security and development

Belarus only sent its foreign minister to the summit - where other nations were represented by prime ministers and presidents - despite an invitation addressed to Lukashenko for the first time, as he had been on an EU sanctions list during previous Eastern Partnership summits.

Lithuanian President Dalia Grybauskaite said she believed Russia was behind Lukashenko's decision to decline the invitation to the summit.

"Moscow, not Minsk, makes the decisions on where he [the president] goes," she told a Lithuanian radio station.

British Prime Minister Theresa May also had harsh words for Russia, noting that the summit was an opportunity to discuss how to tackle "shared challenges" in security and development.

"We must be open-eyed about the actions of hostile states like Russia, who threaten the potential growth of the eastern neighbourhood and who try to tear our collective strength apart," she said.

At the summit, the leaders will take stock of recent achievements, such as visa liberalization for citizens of Ukraine and Georgia when travelling to the EU.

They will also discuss how to cooperate further to create stronger economies, governance, connectivity and societies in the six participating countries.

The event is expected to be overshadowed by negotiations on the sidelines about Britain's exit from the EU, thanks to May's presence.