Russia's attempt to occupy the Sea of Azov must be stopped, including under the UN Convention on the Law of the Sea and by strengthening the sanctions policy, Ukrainian President Petro Poroshenko has said.

"Kremlin has no intention to stop. After occupation of Crimea, it aims now at occupation of the Sea of Azov between Ukraine and Russia," Poroshenko said at the General Debate of the 73rd session of the UN General Assembly in New York on Wednesday.

"Such brutal actions must be rejected as illegal, including under the UN Convention on the Law of the Sea. They require a strong response, including an enhanced sanctions policy and other targeted measures," he said.

Poroshenko noted that after the illegal construction of the bridge across the Kerch Strait, Russia launched a systematic disruption of freedom of international navigation through the Kerch Strait for Ukrainian and foreign ships.