Leonyd Osavolyuk, the director of Ukrainian Foreign Ministry's department for territorial affairs, said earlier in the week that Moscow was attempting to shift the border in the Kerch Strait, and in doing so was ignoring norms of international law.
"It is unclear which international regulations the Ukrainian diplomat is talking about Russia ignoring," Russian Foreign Ministry spokesman Andrei Nesterenko said.
He added that such statements by Ukrainian diplomats do not advance inter-ministerial dialogue or strengthen trust in bilateral relations.
"Unfortunately ... the Ukrainian diplomat has been recently making disrespectful statements in regard to Russia," the spokesman said.
The two countries have been in dispute over the maritime boundary since the early 1990s. Ukraine insists that a national border be drawn in the Kerch Strait, which links the Sea of Azov to the Black Sea, that matches the administrative border that existed between Russia and Ukraine in the former Soviet Union.
Russia maintains that inland water areas were not delimited between the former Soviet republics and therefore this principle is not applicable.
