The French government decided on Sunday to raise the national security alert system Vigipirate to its highest level to deal with the potential threat the country is facing after Friday's deadly terrorist attack in Russia's capital Moscow.

French President Emmanuel Macron convened a defense and security meeting Sunday night at the Elysee Palace in the wake of the attack in Moscow, Prime Minister Gabriel Attal said on his X account.

"In light of ISIS's alleged attack and the threat to our country, we have decided to elevate the Vigipirate status to the highest level: attack emergency," Attal added.

At least 137 people were killed in the terrorist attack at a concert hall in Moscow on Friday. Russian President Vladimir Putin declared March 24 a day of national mourning in a televised national address on Saturday.