As reported by Censor.NET citing UNIAN, Volker told the Voice of America news outlet that the United States' European allies could move to bar Russian vessels coming from Crimea or the Azov Sea from European ports.
He said the move was suggested recently by Annegret Kramp-Karrenabaue, general secretary of Germany's ruling Christian Democratic Union and an aspiring successor to outgoing German Chancellor Angela Merkel.
"It is a very strong measure and a very creative one," Volker told VOA. "We'll see if they pursue it."
He said the United States wants such measures to put pressure on Russia and "get to the point at which Russia is willing to negotiate a solution."
On Nov. 25, Russian border vessels committed aggressive actions against three Ukrainian ships that set sail from the port of Odesa to the port of Mariupol in the Azov Sea. After that, Russian special forces opened fire on the Ukrainian tugboat Yany Kapu, small armored artillery boats Berdiansk and Nikopol in the Kerch Strait and seized them. There were 23 sailors on board the ships, and six of them were wounded.
Russia announced its intention to try detained Ukrainian sailors for allegedly illegal crossing of the Russian state border.
On Nov. 26, the UN Security Council held an emergency meeting on the situation in Ukraine related to the latest developments in the Black and Azov Seas.
Later on the same day, Ukraine's parliament gave the green light to a presidential decree on the introduction of martial law for 30 days in 10 regions of Ukraine – Vinnytsia region, Luhansk region, Mykolaiv region, Odesa region, Sumy region, Kharkiv region, Chernihiv region, Kherson region, Donetsk region and Zaporizhia region, as well as the inland waters of the Azov-Kerch water area.
On Nov. 28, the Russian rubberstamp district court of Simferopol city in Crimea arrested 24 Ukrainian sailors, who had been captured by Russian FSB near the Kerch Strait, for two months. They all face six years in prison.