Photo from UNIAN

Five ex-presidents from Poland and Ukraine have issued a joint appeal for reconciliation between their countries amid growing nationalism and provocations from Russia that have strained their relations.

The ex-presidents expressed concerned about the strains, saying that unity is now needed given "the challenge of Russian aggression to Ukraine," as reported by RFE/RL.

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The appeal was presented at a May 28 news conference in Warsaw by the two former Polish presidents, Aleksander Kwasniewski and Bronislaw Komorowski.

It also was signed by former Ukrainian presidents Leonid Kravchuk, Leonid Kuchma, and Viktor Yushchenko.

Poland for years was one of the strongest advocates in the European Union and NATO for bringing Ukraine into the Western fold. That position infuriated Moscow.

But Polish-Ukrainian ties have been strained recently over disagreements rooted in historical grievances.