Where does Crimea stand in negotiations between Russia and Ukraine?

Crimea has come up time and again throughout the ceasefire negotiations between the US, Russia and Ukraine. In recent weeks, there have been media reports that the United States has been trying to pressure Ukraine to make territorial concessions, including Crimea, in exchange for a ceasefire. The World's Daniel Ofman reports on the history of Crimea, and it's status within ceasefire talks.