Ukraine war live updates: Moscow defends U.S. drone crash; British and German fighter jets intercept Russian aircraft - CNBC

Bulgarian President Rumen Radev held talks Wednesday with his visiting Romanian counterpart as the two neighbors and NATO allies signed a cooperation agreement to boost bilateral ties amid Russia's ongoing war in Ukraine.

Russian opposition leader Alexei Navalny, lawyers Olga Mikhailova and Vadim Kobzev are seen on a screen via a video link during a court hearing at the IK-2 male correctional facility, in the town of Pokrov in Vladimir Region, Russia February 15, 2022.

Locals gather next to a grocery shop as grill meat on the street on east Chasiv Yar nearby Bakhmut frontline as fighting continues between Ukrainian forces and Russian troops for control of the city in Donetsk Oblast Ukraine on March 12, 2023.

U.S. officials told Russia's ambassador to the United States that Moscow has to be more careful when flying in international airspace, White House spokesman John Kirby said on Wednesday, following the crash of a U.S. military drone into the Black Sea after being intercepted by Russian fighter jets.

Analysts at the Institute for the Study of War say the incident is unlikely to cause an escalation between the countries, however, noting Tuesday that "Russian forces have used coercive signaling against US and allied flights and naval vessels for decades in multiple theaters without triggering conflict."

Ukrainian military analyst Oleh Zhdanov said Ukraine was suffering losses among reserves it intended to use in planned counteroffensives against Russian forces, expected in late spring, and noted in an interview reported by Reuters that, "we could lose here everything we wanted to use for those counter-offensives."