The decision of the International Tribunal for the Law of the Sea to free Ukrainian sailors, whom Russia seized together with ships in the Kerch Strait in 2018, is illegitimate. This incident is not under the jurisdiction of the International Tribunal.
[Issuing passports to people in Donbas] is Russia’s humanitarian response to a situation which has become unbearable, where people are deprived of basic human rights
In Donbas, the new Russian passport holders will get fewer rights than those in Crimea. Yet this is indeed a humanitarian act and will be much appreciated by the Donbas residents.
Russian decree on enabling the simplified issuing of passports in certain areas of Ukraine's Donetsk and Luhansk regions is considered an attack on Ukraine's sovereignty. See here for background.
According to the EU, the timing of such a decision immediately after Ukraine’s Presidential election, which demonstrated Ukraine's strong attachment to democracy and the rule of law, shows Russia’s intention to further destabilise Ukraine and to exacerbate the conflict.
Since 2014, the Ukrainian government has required citizens in Donetsk and Luhansk, which are not controlled by Kyiv, to register as internally displaced persons in government-controlled areas of Ukraine in order to receive their pensions and other entitlements.