Polish President Andrzej Duda said after his visit to Kiev that he believes it is necessary to further strengthen the eastern flank of NATO.

He said this in a commentary to Polish media, PAP reported.

"NATO must act decisively, strengthen the eastern flank and continue a consistent policy of containing the potential aggressor - Russia. This is what we expect from the Alliance, for it to be a truly defensive alliance and to remain the strongest alliance in the world that has never failed," Andrzej Duda said.

He said he expects solutions from the upcoming Madrid summit to ensure that the eastern member states feel protected.

"I don't need to tell anyone about the danger of Russian imperialism. President Lech Kaczynski said this in Tbilisi, Georgia, fourteen years ago. He then prophetically said what might happen in the future. And, unfortunately, Russia attacked Ukraine in 2014, and has now attacked for the second time," Andrzej Duda said.

Recall that on May 22 Andrzej Duda came to Ukraine and addressed the Verkhovna Rada, becoming the first leader of a foreign country to personally address the Ukrainian parliament after February 24.