"Some politicians in Europe are ready to believe that there is a chance of good will [from Russia]," Tusk said, adding that he is "more skeptical" and believes that Moscow could attempt to cause a rift among European leaders so a "a permanent effort" is needed to guard the European Union.
Former Prime Minister of Poland, Tusk has listed the strengthening of Euro-Atlantic relations as one of his main priorities since becoming the leader of the European Council.
The West has imposed several rounds against Russia over its alleged involvement in the Ukrainian crisis, claims that Moscow has repeatedly denied. The EU has stressed that the lifting of the sanctions regime depends heavily on the successful implementation of the Minsk truce agreements, signed last month.
On Saturday, EU foreign policy chief Federica Mogherini said the situation in eastern Ukraine has improved since the ceasefire deal was signed between Kiev and the self-proclaimed people's republics of Donetsk and Luhansk (DPR and LPR).
The agreement was achieved on February 12, after 16-hour talks between the leaders of Germany, Russia, France and Ukraine.
