On June 4, 2015, the Cabinet of Ministers of Ukraine by its Resolution № 367 approved the Procedure for entry/exit from the temporarily occupied territory of Ukraine.
The key items of the Regulation are:
Foreigners and stateless persons shall entry/exit temporary occupied territory through checkpoints with passport document and special permit issued by local subsidiary of the State Migration Service of Ukraine. Special permit is issued by local units of the State Migration Service of Ukraine. To apply, a foreigner or stateless person shall submit: application, passport, document confirming legal stay in Ukraine, copy of the page of passport with personal data and its translation into Ukrainian, documents specifying the purpose of the visit to the temporary occupied territory, proof of sufficient funds for staying in Ukraine, three photos 3,5x4,5 cm. Any person violating the Regulation will be held responsible according to the legislation of Ukraine.
Official checkpoints are following:
Information about people entering/exiting the temporarily occupied territory of Ukraine will be processed by authorized officials of the state border authority of Ukraine in the relevant database.
Additional information in Ukrainian is available here.