WASHINGTON (Reuters) - The U.S. military said on Thursday it carried out an “extraordinary” flight over Ukraine under the Open Skies Treaty to reaffirm its commitment to the country after Russia seized three Ukrainian naval vessels off Crimea.

“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 in a statement.

“The United States seeks a better relationship with Russia, but this cannot happen while its unlawful and destabilizing actions continue in Ukraine and elsewhere.”