Dec. 6 (UPI) -- The U.S. Department of Defense announced Thursday that the United States and allies conducted an extraordinary flight over Ukraine after a Russian ship seized Ukrainian vessels and soldiers.
The Pentagon condemned Russia's actions, adding the timing of the flight was intended "to reaffirm U.S. commitment to Ukraine and other partner nations" and that the U.S. is "resolute" in its support of the security of European nations.
"Russia's unprovoked attack on Ukrainian naval vessels in the Black Sea near the Kerch Strait is a dangerous escalation in a pattern of increasingly provocative and threatening activity," the Pentagon said. "The United States seeks a better relationship with Russia, but this cannot happen while its unlawful and destabilizing actions continue in Ukraine and elsewhere."
The Open Skies Treaty permits each of the 34 state parties the right to gather information about the military forces and activities of other state parties, but an extraordinary flight allows countries to conduct the flights on a bilateral basis.
Thursday's flight was conducted with an agreement between Ukraine and the United States, CNN reported.
A total of 25 US military personnel took part in the flight, including eight Defense Threat Reduction Agency personnel and a 17-person air crew from the 55th Wing out of Offutt Air Force Base, Nebraska, Pentagon spokesman Eric Pahon said.
U.S., Canadian, German, French, United Kingdom, Romanian and Ukrainian observers were aboard the flight.
The last "extraordinary" observation flight over Ukraine was in 2014 in response to Russia's military intervention in Crimea.
Thursday's flight came after Russia rammed a Ukrainian tugboat and seized three vessels as well as 24 sailors on Nov. 25.