Head of Ukraine's State Border Guard Service Petro Tsyhykal has accused Russia of hampering the passage of ships visiting Ukrainian ports in the Kerch Strait.

"There is constant inspection of vessels in the Kerch Strait which visit Ukrainian ports for economic purposes... There are virtually no such vessels which don't get inspected, especially those bound for Ukraine. An artificial queue is being created, and our vessels take much longer to inspect and are the last to be let go," Tsyhykal was quoted by his agency as saying on Wednesday.

He also asserted that Russia's coastal guard comes too close to the Ukrainian shores of the Sea of Azov. "The situation is being aggravated by the sea being considered an inside one between two countries. So it is difficult to determine clear boundaries of territorial waters," Tsyhykal said.