Ukraine sent a note of protest to the Russian Federation, 11 August 2017, in connection with the introduction by the Russian Federation of a ban on navigation through the Kerch Strait during August and September 2017, related to the construction of a bridge across the Kerch Strait. Ukraine objects to both the ban and construction.
For further information, see here. Also note the pending Dispute Concerning Coastal State Rights in the Black Sea, Sea of Azov, and Kerch Strait (Ukraine v. the Russian Federation), PCA Case No. 2017-06, previously reported here.