The U.S. Special Representative for Ukraine Kurt Volkers has demanded that Russia releases the Ukrainian sailors taken captive in the Kerch Strait in late November by Christmas.
Volkers spoke with VOA on Monday in Washington, explaining that the United States and its Western allies are considering a number of options to prevent Russia from asserting any more "unilateral control" in the shared waters of the Azov Sea.
"We don't accept and will not accept Russia's claimed annexation of Crimea," he said, underlining the stance that the United States has taken since Russia's so-called annexation of eastern Ukraine's Crimean Peninsula in 2014.
Noting that the waters of the Azov Sea are subject to a bilateral arrangement between Ukraine and Russia, he said, "We don't accept that the territorial waters around Crimea are Russian.
They are Ukrainian. We don't accept, therefore, that Kerch Strait is completely Russian. We believe it is shared sovereignty."