MOSCOW, September 25. /TASS/. Nullifying a treaty between Russia and Ukraine on cooperation in the Sea of Azov will entail serious consequences for Kiev, Director of the Foreign Ministry’s Second Department for the Commonwealth of Independent States Andrei Rudenko told reporters on Tuesday.

"If they make this decision [to exit the treaty of the Sea of Azov], then it’s up to them. Naturally, this will trigger certain consequences for both Ukraine and Russia," Rudenko cautioned.

Russian President Vladimir Putin and then Ukrainian head of state Leonid Kuchma signed the treaty between Russia and Ukraine on cooperation in the Sea of Azov and the Kerch Strait on December 24, 2003 in Kerch.

Based on this pact, which went into effect on April 23, 2004, the two countries defined the status of the Sea of Azov and the Kerch Strait recognizing them as their historic domestic waters. The document outlined the terms for transportation of merchant vessels and warships in these waters as well as Russian-Ukrainian cooperation, including their joint navigation. Any disputes related to the treaty need to be solved through "consultations and talks, and also other peaceful means."

Ukraine’s parliament, the Verkhovna Rada, has repeatedly called for terminating this treaty. A bill on severing this agreement was registered with the parliament back in 2015. However, the Foreign Ministry and some Ukrainian security agencies cautioned the parliament against denouncing the document, saying that this would result in the blocking of Ukrainian ports in the Sea of Azov.

Tensions flared up around the use of the Sea of Azov’s waters on May 25, when Ukraine’s Border Service detained Russia’s Nord fishing vessel there. Only two sailors managed to return home, while the other crewmembers were detained because Ukraine’s Border Service considered them Ukrainian nationals residing in Crimea.

After that, Russia’s border guards stepped up their inspections of Ukrainian fishing ships, while Kiev said it was important to beef up its military presence in the Sea of Azov "to counteract to Russian border guards."

The second initiative on terminating the treaty was registered with the parliament by a group of MPs from the Self Reliance party in July 2018. However, Deputy Foreign Minister Elena Zerkal said Kiev was not planning to denounce the treaty with Russia on cooperation in the Sea of Azov since this would enable Moscow to announce its territorial claims.