"I believe that it is not impossible that one day in the future, a Ukrainian president may stand before this house, in the same role as I do today," Ratas said.

"In the 21st century we must not accept aggression against a European country or the illegal annexation and occupation of part of its territory," he added.

Ratas also referred to the European Parliament's 1983 resolution not to acknowledge the Soviet occupation of the Baltic states. "Were it not for the 1983 European Parliament resolution on Soviet-occupied Estonians, Latvians and Lithuanians, perhaps I would not be standing in front of you today," Ratas said.

"It is clear that the European Union must assume greater responsibility for security in and around Europe. No single country is able to stand up to the threats we face, or solve these challenges alone," he added.

Ratas also expressed his support of closer cooperation within the European Union.