"Petro Poroshenko informed about the rude act of aggression of Russia against Ukraine in the waters of the Kerch Strait and the actions of Ukraine in response, including the introduction of martial law," - said in a statement on the website of the President of Ukraine.
It is noted that Merkel expressed concern and said that she would do everything to de-escalate the situation.
On November 25, the FSB of Russia announced that three ships of the Ukrainian Navy had illegally crossed the Russian border, after which they were detained.
Earlier Poroshenko signed a decree on the introduction of martial law in Ukraine.
The Russian Foreign Ministry protested the incident in the Kerch Strait.