The French Senate has begun debating a bill that makes it illegal to deny as genocide the mass killings of Armenians during Turkey's Ottoman era nearly a century ago — despite Turkey's threat of more sanctions.

French senators were to vote on the legislation late Monday.

Turkish Foreign Minister Ahmet Davutoglu told reporters ahead of the debate that Ankara is ready to implement new and permanent measures against France unless the law is rejected. He did not elaborate.

France's lower house of parliament passed the bill last month. The move prompted Turkey to recall its ambassador to France and ban the French navy from using Turkish territorial waters. Ankara also imposed restrictions on the use of Turkish air space by French military aircraft.

The French foreign ministry called on Turkey not to overreact, and said France considers Turkey a “very important ally.”

Paris police separated rival demonstrations — one pro-Turkish and one pro-Armenian — outside the upper house of parliament as the debate got under way.

The bill says anyone denying the killings of Armenians by Ottoman forces constituted genocide faces a $60,000 fine and up to one year in jail. Paris recognized the killings as genocide in 2001, but imposed no penalty over the issue.

Armenia says 1.5 million Armenians were killed during World War I by troops of Turkey's Ottoman Empire. Turkey has acknowledged the loss of Armenian lives, but says the death toll is exaggerated and does not amount to genocide. It says the deaths were the result of civil war.

French President Nicolas Sarkozy last week wrote a letter to Turkish Prime Minister Recep Tayyip Erdogan, saying the bill does not single out a particular country.

Mr. Erdogan has accused France of committing genocide in Algeria more than 60 years ago. He said French colonialists massacred 15 percent of Algeria's population starting in 1945. He also accused Mr. Sarkozy of pandering to the hundreds of thousands of French citizens of Armenian descent heading into his re-election bid this year.

Turkey's president, Abdullah Gul, has said Mr. Sarkozy is “prejudiced” against Turkey.

Relations between France and Turkey, both members of NATO, have been frozen due to French opposition to Turkey's bid to join the European Union.