U.S. President Joe Biden tried to send Vladimir Putin an ultimatum about the consequences of any invasion of Ukraine in an hourlong conversation that left both sides at an impasse and Russia’s intentions unclear.

Biden warned his counterpart in Moscow that Russia would face "severe costs.” For his part, the Russian leader accused the U.S. of failing to provide him with security assurances he needs to back down.

The Kremlin characterized the talks as businesslike and balanced. Briefings by both sides afterward stuck to familiar talking points, providing few clues on where things go from here.