The US military has repositioned a squadron of F-16 fighters from Germany to Romania, 'to reinforce regional security'.
Satellite picture of Russian battle group formation in Soloti, Russia.
The United States said it is relocating its embassy in Kyiv to the western Ukrainian city of Lviv, citing a "dramatic acceleration" in the buildup of Russian forces at the country's border.
Staffing at the US embassy in Kyiv had already been drastically reduced after the US ordered the departure of most diplomats and halted consular services.
A small consular presence had already been put in place in Lviv, about 70 kilometers from the Polish border.
Satellite pictures of Russian SU-34 fighter aircraft deployed at Primorsko Akhtarsk airbase in Krasnodar Krai in Russia.
Amid the escalating crisis, Britain will send a small number of troops to Lithuania, in response to "pressures along its border with Belarus".
Although Lithuania is a NATO member, the personnel will not be sent through the Western military alliance but bilaterally.
Britain has announced a flurry of troop deployments in recent weeks, sending an additional 350 soldiers to Poland to help shore up NATO's eastern flank against any perceived Russian aggression.
They join the 150 soldiers Britain already contributes to NATO's enhanced forward presence there.
Satellite pictures of armour and self-propelled artillery loaded on flat cars and railyard in Yelnya, Russia.
Dozens of the 350 troop reinforcements promised by Germany began arriving in NATO ally Lithuania on Monday amid regional tensions over Russia's troop build-up around Ukraine.
A military transport plane carrying German soldiers arrived in Kaunas -- the Baltic state's second-largest city -- to begin the deployment.
With more than 100,000 Russian troops massed on the Ukrainian border, fears are mounting that a major conflict could break out in Europe.
Satellite pictures of Russian combat equipment in Pogonovo, Russia.
Fearing an invasion of Ukraine by Russia, many countries are urging their citizens there to leave and are cutting back their diplomatic staff.
Moscow has recalled some of its diplomatic staff, saying it fears "provocations".
Canada is closing its embassy in Kyiv temporarily, moving diplomatic operations to Lviv, as is Australia.
European Union bodies recommended non-essential diplomatic personnel in Kyiv leave the country and telecommute from abroad.
Russian Navy's diesel-electric Kilo class submarine Rostov-on-Don sails with an naval ensign of the Russian Federation, also known in Russian as “The Andreyevsky Flag” on it through the Bosphorus Strait on the way to the Black Sea past the city Istanbul as Sultanahmet mosque and Hagia Sophia mosque.
Australia has directed all remaining embassy staff in Kyiv to evacuate.
The evacuation follows similar announcements from the United States and Canada and comes after a frenzy of telephone diplomacy failed to ease mounting regional tensions.
Ukraine's old navy -- stationed almost entirely in the Crimean port of Sevastopol -- practically vanished when Russia annexed the peninsula and took all its ships in 2014.
Military analysts say Ukraine now has just one major warship and a dozen or so patrol and coastal craft of the type captained by Surkov.
Russia has sent six more warships into the region for a week of naval drills involving dozens of navy ships starting this weekend.
Ukrainian military analyst Mykola Beleskov says Russia now has 13 major battleships in the Black Sea on Ukraine's southwestern coast that can enter the landlocked Sea of Azov on its southeast at any point.
The UN estimates that the entire separatist conflict has claimed more than 14,000 lives and forced 1.5 million from their homes.
The US military has repositioning a squadron of F-16 war planes from Germany to Romania, "to reinforce regional security" in the midst of flaring tensions with Russia over Ukraine.
US President Joe Biden has sent 3,000 US troops to Germany, Poland and Romania to bolster allies on NATO's eastern flank, as Western states fear a Russian invasion of Ukraine.
The move comes as Russia began large-scale military drills in Belarus, right on the border with Ukraine, which is at the center of high tensions between Russia and the West.
Amid the crisis, the European Union accused Russia, as the Ukraine crisis churned, of trying to divide EU members by sending letters to individual countries seeking clarification of their stance on a principle of international security.
Moscow says the concept of indivisible security, enshrined in international treaties, means that the security of one country is inextricably linked to that of another and that an enlargement of the NATO defence alliance to include the former Soviet republics of Ukraine and Georgia would automatically threaten Russia.
However, Russian foreign minister Sergei Lavrov said that Western threats towards Moscow would do nothing to ease tensions over Ukraine.
"Ideological approaches, ultimatums, threats -- this is the road to nowhere," Lavrov said at the start of talks with his British counterpart Liz Truss in Moscow.