Europe will stay united in support of Ukraine: Donald Tusk

European Council President Donald Tusk on Monday condemned Russia's seizure of Ukrainian navy vessels in the Kerch Strait.

"I condemn Russian use of force in the Azov Sea. Russian authorities must return Ukrainian sailors, vessels and refrain from further provocations," Tusk said after a phone call with Ukrainian President Petro Poroshenko.

"Europe will stay united in support of Ukraine."