Latvian Foreign Minister Edgars Rinkēvičs said that Russia should be designated as a state-sponsor of terrorism following the attack on Friday that killed Ukrainian prisoners of war.
Speaking on Sunday to Politico in a phone interview, he also urged again to isolate Russia further on an international scale.
"We see all the brutality of Russian forces, that actually resemble a lot of ISIS (Daesh), who we have been always calling a terrorist organization," he said.
"Let's call a spade a spade."
Ukraine and Russia had blamed each other for attacking the prison containing the Ukrainian prisoners of war in the eastern region of Donetsk.
He also urged other countries to aid Ukraine saying that "the only way to move forward is to strengthen the current strategy, which is support to Ukraine, send more military aid."
Rinkēvičs also urged for asset confiscation of the Russian government and visa issuing restrictions for Russians with the exemption of humanitarian reasons.
"Society needs to feel it," Rinkēvičs said, claiming that a big part of the Russian people supports the policies of the Kremlin.
"If we condemn countries like Iran," Rinkēvičs said, "Russia is not different."
Kyiv had also asked before its Western partners to designate Russia as a "terrorist state."
"Our state received many signals from different countries condemning the Russian terrorist act in Olenivka," Ukrainian President Volodymyr Zelensky said in a video message late Saturday.
The remarks of Rinkēvičs come following the Russian gas company Gazprom announced on Saturday that it was halting gas supplies to Latvia for allegedly breaching contract terms.