"It is wrong and unjust for our European friends to press Turkey on these issues," he said. "They should know that it is not possible for demands imposed on us and devoid of just foundations to be accepted."
Turkey has recently faced mounting calls from within the EU, which it hopes to join, to acknowledge the massacres as genocide, something it systematically rejects.
Some EU politicans have said that the genocide claims will be one of the issues Turkey must address as it prepares to launch lengthy membership talks with the EU on October 3.
"These claims (of genocide) upset and hurt the feelings of the Turkish nation," Sezer said. "What needs to be done is research, investigate and discuss history, based on documents and without prejudice.
"The basis of such discussions should be scientific and not political," he said.
The Armenian massacres of World War I are one of the most controversial episodes in Turkish history.
Armenians say up to 1.5 million of their kinsmen died in orchestrated killings nine decades ago during the final years of the Ottoman Empire, the predecessor of modern Turkey.
Turkey, on the other hand, argues that 300,000 Armenians and thousands of Turks were killed in what was civil strife during World War I when the Armenians, bacvked by Russia, rose against their Ottoman rulers.