The dock-landing vessel USS Fort McHenry transited the Dardanelles Strait en route to the Black Sea on Sunday, making it the first U.S. Navy ship to enter the tense region since Russia seized three Ukrainian vessels in November in the Kerch Strait.

Navy officials say the Fort McHenry is conducting a regularly scheduled Black Sea operation. This is the first Navy ship to enter the Black Sea since August, when the USS Carney, an Arleigh Burke-class destroyer, and the fast-transport vessel USNS Carson City worked separate missions there.

“We routinely operate in the Black Sea consistent with international law and the Montreux Convention and will continue to do so,” Cmdr. Kyle Raines, 6th Fleet spokesman, said. “We also continue our call for Ukraine and Russia to seek a diplomatic resolution to their dispute.”

Officials wouldn’t say when another ship might cruise into the Black Sea, citing the standard Navy policy of not discussing future operations.

The Fort McHenry is a transport vessel equipped with defensive weaponry such as machine guns, small cannons and short-range anti-missile systems. It has little offensive capability.

Russia has viewed any U.S. naval ship in the Black Sea as an intrusion since it seized the Crimean Peninsula in 2014. But maintaining Black Sea patrols after the Kerch Strait incident is important to show a commitment to protecting partners against Russian aggression, said Michael Petersen, director of the Naval War College’s Russia Maritime Studies Institute.

“The U.S. has committed to upholding international law, which Russia has consistently violated in the Black Sea,” Petersen wrote in an email exchange last week.

The U.S. and NATO allies have denounced Russia opening fire on three Ukrainian vessels near the Sea of Azov and detaining 24 crew members but shown little interest in taking direct action against Russia.

Ukraine is not a NATO member, so allied nations are not compelled to defend it against an aggressor like Russia, Petersen said. This makes Ukraine more vulnerable to Russia, he added.

“The risks of using military force against NATO in Eastern Europe are orders of magnitude greater than they are in the case of Ukraine,” Petersen said.

wyland.scott@stripes.com

Twitter: @wylandstripes