President Abdullah Gul of Turkey has urged France to drop a draft law that, if approved by parliament, would make denying the Armenian genocide during World War I a crime.
Mr Gul said Turkey could not accept the bill.
France's lower house of parliament is due to consider a bill that proposes a one-year prison term and a heavy fine.
Turkey has warned of irreparable damage to ties if the legislation is passed.
Armenians say up to 1.5 million people died during mass deportations. Turkey puts the figure at closer to 300,000.
In a statement, President Gul said the proposed legislation, which is due to go before the National Assembly on Thursday, denied Turkey the freedom to reject "unfair and groundless accusations".
He also suggested that France was jeopardising centuries of friendship.
A delegation of Turkish MPs and businessmen has travelled to Paris to lobby against the bill.
The BBC reports trade sanctions against France have been mooted. Almost 1000 French businesses are said to be active in Turkey.
Last week, Prime Minister Recep Tayyip Erdogan wrote to President Nicolas Sarkozy warning him that bill was "hostile" and directly targeted Turkey and Turks living in France.
Mr Erdogan also told a news conference on Saturday that the National Assembly should instead look into France's actions in Africa.
