KYIV, Sep 13 – President Petro Poroshenko will open a plenary session of the 14th annual meeting of the Yalta European Strategy (YES) in Kyiv on September 15.

The president's speech will be devoted to Ukraine's role in the changing world, the press service of YES said on Wednesday.

The discussion of the participants of the conference with Poroshenko will be moderated by President of the Council on Foreign Relations Richard Haass.