Vladimir Putin
Vladimir PutinReuters

Russian President Vladimir Putin acknowledged on Monday that the terrorists who killed 139 people at a suburban Moscow concert hall this past Friday are “radical Islamists,” but once again repeated his accusation that Ukraine could have played a role in the attack, The Associated Press reported.

Two days after the Islamic State's (ISIS) Afghanistan affiliate claimed responsibility for the attack at the music venue, Putin acknowledged during a meeting with government officials that the killings were carried out by extremists "whose ideology the Islamic world has been fighting for centuries.”

At the same time Putin, who declared over the weekend that the four attackers were arrested while trying to escape to Ukraine, said investigators haven't determined who ordered the attack, but that it was necessary to find out “why the terrorists after committing their crime tried to flee to Ukraine and who was waiting for them there.”

"We are seeing that the US, through various channels, is trying to convince its satellites and other countries of the world that, according to their intelligence, there is allegedly no Kyiv trace in the Moscow terror attack — that the bloody terrorist act was committed by followers of Islam, members of the Islamic State group,” Putin said in Monday’s meeting.

He added that “those who support the Kyiv regime don't want to be accomplices in terror and sponsors of terrorism, but many questions remain.”

Kyiv denies any involvement in this attack. On Saturday night, Ukrainian President Volodymyr Zelenskyy accused Russian President Vladimir Putin of seeking to “shift the blame” onto Kyiv for the Moscow attack.

“What happened yesterday in Moscow is obvious: Putin and the other scum are just trying to blame it on someone else,” Zelenskyy announced.

The US National Security Council said in no uncertain terms on Saturday night that Ukraine had nothing to do with the deadly concert attack.

"ISIS bears sole responsibility for this attack. There was no Ukrainian involvement whatsoever," NSC spokesperson Adrienne Watson said in a statement quoted by NBC News.

Watson noted that the United States "shared information with Russia about a planned terrorist attack in Moscow."