Ukraine's fifth President Petro Poroshenko has said he sees pro-Russia forces' revenge in the proposal on granting official status to the Russian language in Donbas. Poroshenko called on other political forces to unite and support a Euro-Atlantic charter developed by the European Solidarity Party he leads.

"The situation has developed in such a way that creeping pro-Russia revenge is becoming more and more obvious. There was the proposal to grant Russian language official status in Donbas. But trading languages will not bring Ukraine any dividends, and will not stop Russia. The main idea behind the revenge is to stop our progress toward the European Union and NATO and to bring the whole of Ukraine, from Donbas to Halychyna, back under Russia's influence," he said on Facebook on Tuesday.

Poroshenko said Russia understands that Ukraine's accession to the EU and NATO would provide Ukraine with a complete guarantee of peace, security and independence.

Poroshenko said diplomats and lawyers of European Solidarity have developed a fundamental document, dubbed "Euro-Atlantic Charter," and called on political forces to support it.

"This is our credo. It is like an oath, and like a plan of agreed-on steps of various political forces aimed at accelerating Ukraine's accession to NATO. The charter provides clear obligations, which will not let anyone hide their tails if the political landscape changes. We believe that other political forces will support the charter. Only by joining efforts we can achieve our goal, which is peace and security through NATO membership, and prosperity through accession to the European Union," Poroshenko said.