But Kremlin spokesman Dmitry Peskov dismissed the rumours as "absurd" and described them as "another attempt to generate tension".
Kyiv says the sailors did nothing wrong, and its ships have the right to pass through the strait to reach Ukrainian ports in the Sea of Azov.
Polygraph.info reached out to Omelyan for comment on November 30. Russia's brinkmanship in the Sea of Azov could also presage a more aggressive pursuit by Moscow of its strategic interests across the entire Black Sea region, and has profound implications for both regional and global security.
In response to the seizure of the ships, Poroshenko convinced the Ukrainian parliament to implement martial law in ten border regions.
Omelyan, who accused Russian Federation last week of blocking Ukrainian cargo trying to pass through the strait, said the ports of Berdyansk and Mariupol were partially unblocked thanks to a "stern global response". "There is already a lot of North Atlantic Treaty Organisation in the Black Sea".
It is Russia, not Ukraine, that protects Europe from barbarism, militarism and aggression, Russian Foreign Ministry spokeswoman Maria Zakharova said, commenting on Ukrainian President Petro Poroshenko's allegations that Russia is planning to seize Mariupol and Berdyansk. The president urged the worldwide community and democratic world leaders to join her in the statement and to condemn the Russian aggression clearly, collectively and immediately, and demand a stop to the aggression.
The Azov Sea is world's most shallow sea. All three Ukrainian ships were detained in the Black Sea.
The official told reporters Tuesday that during a North Atlantic Council meeting on Black Sea security, the United States "reiterated that we condemn this Russian act of aggression, that Crimea is Ukraine, and that the Russian action in Kerch is a clear military escalation and violation of worldwide law and freedom of the sea". Russian Federation had annexed the Crimean Peninsula in 2014.
Ukraine's leader has called on Germany and its allies to boost their naval presence in the Black Sea to deter Russian Federation from further aggression in the region.
North Atlantic Treaty Organisation nations, individually and through the European Union, have also imposed economic and other sanctions on Russian Federation since it annexed Ukraine's Crimean Peninsula in 2014, but there is little appetite among the allies to broaden those measures. Similarly, other Black Sea littoral states-in particular, Romania-are closely watching Russia's military build-up around the Black Sea and its associated belligerent actions and are revising their strategic calculations accordingly.
"The accusations against Russian Federation have no basis whatsoever", he added.