The latest round of talks between Ukrainian President Volodymyr Zelenskyy and U.S. envoys have ended as they and European allies seek an end to Russia's nearly four-year war.

The NATO issue is what the Kremlin describes as a "root cause" of its war in Ukraine.

Germany is ramping up its military operations amid security concerns over the Russia-Ukraine war. German Defense Minister Boris Pistorious talked about the rearming on "60 Minutes." Isaac Stanley Becker,

Zelenskyy said Russia used more than 450 drones and 30 missiles in the attack.

Two U.S. officials who spoke on the condition of anonymity said the arrangement would be similar to the NATO mutual defense agreement. But crucial details remain unsettled as negotiators seek a deal that Russia will approve.

Ukraine’s domestic security service, the SBU, said Monday that it struck a Russian submarine in the Black Sea port of Novorossiysk, causing critical damage to the vessel and effectively disabling it.

At least three oil tankers have been hit by explosions in what appears to be a stepped up unilateral effort by Ukraine to sink Russia's sanctions-dodging oil sales.