All eyes are now on Vladimir Putin, who will decide how Russia will respond amid fears that Europe could again be plunged into war.
European leaders are working their own diplomatic avenues to end the tensions and worry that talk of a Russian invasion of Ukraine could be deepening divisions among them.
Navalny and eight of his allies — including top aides Lyubov Sobol and Georgy Alburov — were on Tuesday added to the registry by Russia's Federal Financial Monitoring Service.
What's the correct way to call a foreign city — by its English name, if it has one, or by its name in the local language? For the people involved, it can be a serious matter entwined with geopolitics.
Biden said should Russian President Putin move in using the more than 100,000 Russian troops surrounding Ukraine, "it would be the largest invasion since World War II. It would change the world."
The Pentagon said no final decision has been made, but Defense Secretary Lloyd Austin wanted U.S. forces to be ready "just in case" of a Russian invasion of Ukraine.
The situation along the Russia-Ukraine border remains tense, with thousands of Russian troops amassed just across the divide and Ukraine preparing for a possible invasion.
"You have to find ways to live a normal life," says a mother of four in Kyiv. She and her family keep their car full of fuel and plan to take refuge in a village outside the capital if Russia attacks.
Secretary of State Antony Blinken and his Russian counterpart, Sergey Lavrov, ended talks in Geneva with no major breakthroughs but an agreement to keep talking.
President Biden said there was uncertainty among allies about how they would respond to a "minor incursion" by Russia into Ukraine. That led to alarm overseas — and a clean-up at home.
Ukraine's Territorial Defense Forces were set up to train part-time reservists but last year the drills were opened to ordinary citizens — to foster popular resistance if the military is overwhelmed.
The tests of the fast and maneuverable class of weapons that purport to be able to evade missile defense systems, has garnered the attention of the White House, which responded with new sanctions.
Russia forced the West into a flurry of diplomacy this week with its massive troop buildup on its border with Ukraine. Here's a short guide to what the Kremlin wants.
The U.S. and its European allies want Russia to reduce troop buildup along the Ukraine border. Russia wants U.S. troops out of Eastern Europe. Both sides say those demands are non-starters.
Russia's Interfax news, citing the military, reports that 10,000 troops are returning to their "permanent deployment points" from the border region.