Deputy Prime Minister of Crimea, Rustam Temirgaliev, said that the thousands of barricaded Ukrainian soldiers in Crimea would have to swear an oath to Crimean authorities immediately after the referendum or leave, according to KyivPost.

"We can allow them safe passage to Ukraine," he said. "But about 85 percent of Ukrainian troops have already joined Crimean forces."

Temirgaliyev also said Crimean authorities were already taking preparatory steps to adopt the Russian ruble and transition away from the Ukrainian hryvnya within a year.

"In April, Russian rubles will start functioning here," he told journalists, adding that the Hryvnia will stay in use for a year.