UKRAINIAN Defence Minister Stepan Poltorak raised the stakes with Russia today, threatening that Kiev will soon send warships through the Kerch Strait where Russia seized three Ukrainian vessels two weeks ago.

Mr Poltorak sought to justify this move by saying that “otherwise Russia will fully occupy the Sea of Azov.”

Russian border guards opened fire on November 25 on three Ukrainian navy vessels moving through the Kerch Strait near Crimea, which seceded from Ukraine in 2014 to rejoin Russia, seizing the ships and their crews.

The Ukrainian government responded by introducing martial law for 30 days, beefing up its forces on the border with Russia and calling up reservists for training.

Ukraine has ports both on the Black Sea and on the Sea of Azov, which are linked by the Kerch Strait that separates eastern Crimea from mainland Russia.

The Ukrainian Border Guard Service complained yesterday that over 140 ships were stuck on both sides of the strait due to excessive checks and delays. It accused Moscow of creating a bottleneck for Ukrainian ships and preventing them from passing.

Russian Foreign Minister Sergey Lavrov brushed off suggestions that Moscow could release or exchange the 24 Ukrainian seamen captured in last month’s maritime confrontation.

Speaking in Rome at an Organisation for Security and Co-operation in Europe (OSCE) ministerial meeting, he said it was too early to speak about prisoner swaps before Russia’s investigation of the November 25 incident is completed and the naval ratings put on trial for violating the Russian border.

Mr Lavrov brushed off a suggestion by German Foreign Minister Heiko Maas to expand an OSCE monitoring mission to cover the Sea of Azov, saying that Russia “has no need” of any intermediaries or monitors in the area.

Russian ombudswoman Tatyana Moskalkova said yesterday, after visiting three Ukrainian seamen in a Moscow prison hospital, that she “got the impression” that the crew “were not aware that they were committing a crime.”

Lawyer Emil Kurbedinov, who represents the commander of one of the Ukrainian ships, was jailed for five days yesterday after being found guilty of spreading extremist material in a 2013 social media post.