A European Commission official told reporters on Tuesday afternoon that relations with Minsk have improved over the past two years, as shown by the lifting of sanctions in exchange for releasing political prisoners.
In line with Brussels' rules, the official asked for anonymity because he was not authorized to speak with the media.
The heads of the European Commission and the European Council invited Belarusian President Alexander Lukashenko to the Eastern Partnership summit, but he decided to send his foreign minister. Brussels and Minsk have also resumed their regular consultations.
Diplomats say that Lithuanian and Polish officials were critical of the decision to invite Lukashenko. Lithuanian President Dalia Grybauskaitė does not approve the resumption of a closer dialog with Minsk, due to the Astravyets project safety issues and Belarus' joint military exercises with Russia.
Speaking to journalists ahead of Friday's Eastern Partnership summit, the European Commission official said that EU officials will continue to call on Belarus to comply with the highest safety standards.
"We have raised the issue of nuclear power plant on many occasions. There are close contacts between our experts in the Directorate-General for Energy in the European Commission with both Belarus' experts and Lithuanian experts, understanding that Lithuania is only 20 kilometres away from where nuclear power plant is about to be constructed," the official said.
"We have shown and continue to show full solidarity with Lithuania and other neighbouring countries who are concerned about the security of this nuclear power plant", he said.
Lithuanian officials say that the nuclear power plant under construction in Astravyets, some 40 kilometres from Vilnius, does not meet safety and environmental standards, but Minsk rejects the criticism.
In an effort to hinder the project, Lithuania plans to bar access for the plant's electricity to its market. The Lithuanian government two years ago asked Brussels to start EU-level discussions on boycotting unsafe power plants, but it did not receive support either from the European Commission or other member states.