On Sunday, Russia's Federal Security Service (FSB) said that three ships from the Ukrainian Navy — Berdyansk, Nikopol and Yany Kapu — were detained after violating the Russian maritime border, according to Articles 19 and 21 of the UN Convention on the Law of the Sea. The Ukrainian naval ships did not react to legal demands of the vessels accompanying them and made dangerous manoeuvers, the FSB noted.
Ukrainian President Petro Poroshenko said Monday that the imposition of martial law in the country would not affect the situation in Donbass, and did not mean that Kiev would conduct an offensive military operation.
"The introduction of martial law does not mean in any way that Ukraine will conduct any offensive actions. Ukraine will exclusively conduct actions to defend its territory, protect and ensure security of its citizens. It also does not mean a change of position on the contact line in certain areas of the Donetsk and Luhansk regions and other areas," the Ukrainian president said in a speech broadcast by Ukrainian television channels.
According to the president, the possible introduction of martial law in the country does not mean that Kiev is rejecting the Minsk agreements, he added.
"Martial law does not mean our rejection of a political and diplomatic settlement of the liberation of Ukrainian territory. We have intentions to continue to adhere to all international obligations, including the Minsk agreements," Poroshenko said at the NSDC meeting.
"The decision does not provide for immediate mobilisation, but training of the primary reserve pool will be conducted. We must carry out all measures to protect the state as soon as possible," Poroshenko stressed.
Meanwhile, the Ukrainian army opened massive artillery fire on Sunday, shelling residential areas of the self-proclaimed Donetsk People's Republic (DPR).
Russian Foreign Ministry spokeswoman Maria Zakharova criticized Kiev’s provocations as 'gangster methods'.
EU foreign policy spokesperson Maja Kocijancic said Sunday that Brussels had called on Russia and Ukraine to act with maximum restraint in the situation around the Kerch Strait.
"The tensions in the Sea of Azov and Kerch Strait have increased dangerously today […] We expect Russia to restore freedom of passage at the Kerch Strait and urge all to act with utmost restraint to de-escalate the situation immediately," according to the statement, also confirming the position of the EU foreign policy chief that the EU expected Russia to stop inspections of vessels.
"NATO is closely monitoring developments in the Sea of Azov and the Kerch Strait, and we are in contact with the Ukrainian authorities. We call for restraint and de-escalation," according to the statement.
NATO fully supports the sovereignty and territorial integrity of Ukraine, including navigation rights in its territorial waters, it added.
"We call on Russia to ensure unhindered access to Ukrainian ports in the Sea of Azov, in accordance with international law," the statement said.
NATO earlier expressed support for Ukraine at the alliance's July summit, claiming that what it referred to as the 'ongoing militarisation' of Crimea by Russia undermined stability in the region.
The tensions around the Sea of Azov erupted this year after Ukraine detained a Russian vessel, prompting Moscow to boost controls in the area. The tensions further escalated in October when the Ukrainian parliament passed a draft law authorising Kiev to expand maritime controls by 12 nautical miles off its southern coast, purportedly in an effort to counter smuggling in the Black Sea.
Meanwhile, Ukrainian Parliament Chairman Andriy Parubiy said that he was convening an extraordinary session of the parliament at 14.00 GMT on Monday.
"In pursuance of the decision of the National Security and Defence Council of Ukraine and the appeal of the President of Ukraine, on Monday, 26 November 2018, at 16.00 (14.00 GMT), I will convene an extraordinary session of the Verkhovna Rada of Ukraine," Parubiy wrote on Facebook on Sunday night.