Poroshenko explains timing of Russia's attack on Ukrainian ships near Kerch Strait

This marked a new phase in an emerging third-maritime-front between Ukraine and Russian Federation, one likely to keep Europe busy for years to come.

Mr Poroshenko called for the move after Russian forces fired on, boarded and captured three of Kiev's ships on Sunday off the coast of Crimea.

This is the first open armed confrontation between Ukraine and Russian Federation since the annexation of Crimea in March 2014.

"We can not accept this aggressive policy of Russian Federation".

"We do not like what's happening, either way, we don't like what's happening and hopefully it will get straightened out", he said, hours after U.S. Ambassador to the United Nations Nikki Haley condemned Russia for their "outrageous violation of sovereign Ukrainian territory" that marked "yet another reckless Russian escalation".

The seizure of the navy vessels drove tensions to their highest since 2015, when Moscow-backed rebels rose against the Kiev government in the eastern Donbass region, sparking a war that has killed tens of thousands.

The naval boats had been sailing from Odessa to Mariupol, a Ukrainian port on the Azov sea, when they were confronted by the FSB vessels.

Interfax news agency quoted Russia's human rights commissioner, Tatyana Moskalkova, as saying on November 26 that 24 Ukrainian sailors were being detained.

Russian Federation has accused Ukrainian president Petro Poroshenko of manufacturing the clash for domestic political reasons - he is well behind in the polls and there are elections next March. Well, it is clear that this was done on the eve of the presidential election.

Mr Poroshenko has low popularity ratings.

The Ukrainian ships did not respond to the legitimate demands coming from the vessels of the Border Service of the Russian Security Service (FSB) and the Black Sea Fleet that had pursued them in order to stop them immediately and thwart their risky maneuvers.

"Military vessels intruded into Russian territorial waters and did not answer (the border guards)".

The skirmish occurred in the strategically significant Kerch Strait, where a Kremlin-built bridge connects Russian Federation to the southeastern portion of Ukraine that's occupied by Russia-backed forces.

It called on Russian Federation to release the ships and their crews and respect Ukraine's sovereignty.

Poroshenko called on Germany, the largest and wealthiest buyer of Moscow's gas exports, to halt the building of an undersea gas pipeline that would allow Russian Federation to supply Germany directly, cutting out Ukraine.

The episode has raised fears in the West of a wider conflict between the two countries, and Trump said on Tuesday that he might cancel a planned meeting with Putin at the G20 summit in Argentina later this week as a response to "aggression".