Update(11:05ET): Moscow has hit back against Washington by sanctioning top US leadership, including President Joe Biden himself. The punitive retaliation measures extend to the chiefs of the Pentagon, and Secretary of State Antony Blinken and CIA Director William Burns. Russian state media announced in a Tuesday statement:

"Russia on Tuesday sanctioned US President Joe Biden, Secretary of State Tony Blinken, Defense Secretary Lloyd Austin, and ten other administration officials and political figures. Moscow has said that the sanctions are a reciprocal measure, imposed after Washington blacklisted top Russian leaders, including President Vladimir Putin."

Despite the measures being largely symbolic - as it will be essentially impossible for Moscow to actually go after US officials' assets unless they are held in Russia itself (and certainly no top American official is looking to travel to Russia anytime soon) - it signals that tensions with the West are ratcheting fast, with increasingly few off-ramps as the two sides chart a war-footing course.