The territorial destiny of Donetsk is the key issue preventing the conclusion of a peace deal between Ukraine and Russia, U.S. Secretary of State Marco Rubio said Wednesday. “The one remaining item … is the territorial claim on Donetsk. There is active work going to try to see if both sides’ views on this can be reconciled,” Rubio told a U.S. Senate Foreign Relations Committee meeting. According to open-source maps of the conflict, Russian forces now control about 80 percent of the Donbas region. Ukrainian President Volodymyr Zelenskyy has repeatedly vowed that Ukraine will not give up Donbas as part of any ceasefire deal, as that would give Putin a springboard for a future invasion.