Secretary General of the North Atlantic Treaty Organization (NATO) Jens Stoltenberg says that there is no justification for the use of military force by Russia against Ukrainian boats near the Kerch Strait in the Black Sea on November 25.

"There is no justification for the use of military force against Ukrainian ships and naval personnel. So we call on Russia to release immediately the Ukrainian sailors and ships it seized yesterday," he said at a press conference in Brussels after an extraordinary meeting of the NATO-Ukraine Commission on November 26 in a comment on the attack and seizure of three Ukrainian vessels by the Russian special forces.

In his words, the incident is a reminder that there is a war going on in Ukraine.

Read alsoNATO reacts to capture of Ukrainian navy's boats near Kerch Strait – journalist

"Russia's ongoing militarization of Crimea, the Black Sea and the Sea of Azov, poses further threats to Ukraine's independence. And undermines the stability of the broader region," he said.

"So we call on Russia to ensure unhindered access to Ukrainian ports and allow freedom of navigation for Ukraine in the Sea of Azov and the Kerch Strait," he added.

According to him, NATO Allies and Ukraine discussed the serious situation in the Sea of Azov and the Kerch Strait on Monday. Ukraine provided Allies with detailed information on the November 25 incident.

What is more, on Monday morning, Stoltenberg had a phone call with Ukrainian President Petro Poroshenko who requested the NATO-Ukraine Commission meeting. "Because under the NATO-Ukraine Charter, Ukraine can request such a meeting if it perceives a direct threat to its territorial integrity, political independence, or security," Stoltenberg said.

"We will remain in contact with the Ukrainian government to underline our support," he added.