MOSCOW - President Vladimir Putin said on Tuesday that Russia will find out who was behind last month's attack on a concert hall near Moscow that killed at least 144 people.

"We will definitely get to those who ultimately ordered it," Putin told a meeting of Interior Ministry officials. "We paid a very high price, and the entire analysis of the situation must be extremely objective and professional."

Islamic State claimed responsibility for the attack and U.S. officials say they have intelligence showing it was carried out by the network's Afghan branch, Islamic State Khorasan (ISIS-K). Russia says it has evidence the attackers had links to Ukraine, which Kyiv has denied and the United States has rejected as nonsense.