US president also briefed NATO allies on talks with Vladimir Putin as efforts to ease tensions with Ukraine continue.
Vladimir Putin presents US president with demand for guarantees against NATO expansion eastward, Kremlin says.
US president called leaders of France, Germany, Italy and Britain on Monday to discuss their ‘shared concern’.
The warning from the top US diplomat comes as Russia tells Ukraine not to get drawn into US ‘geopolitical games’.
US Secretary of State Antony Blinken says Washington ‘will be prepared to act’ if Russia invades Ukraine.
Black Sea peninsula ‘de jure’ Russian territory, Belarusian president says, prompting backlash from Kyiv.
Jens Stoltenberg urges Russia to be transparent as NATO monitors ‘unusual’ concentration of forces near Ukraine border.
Defence Ministry says Russian naval warship approached US destroyer USS Chafee to force it out of area.
Volodymyr Zelenskyy urges international forum to back Kyiv in its bid to overturn 2014 seizure of Black Sea peninsula.
Day after NATO and Ukraine began Black Sea exercises, Moscow says it has tested Crimean air defence systems.
London dismisses Moscow’s version of events as ‘predictably inaccurate’, while Russia summons UK ambassador.
Ukraine and the EU condemn Russia’s decision to restrict the navigation of foreign military and official ships.
US diplomat leads charge in pressing Moscow to ‘immediately cease its aggression’ in eastern Ukraine, Crimea occupation.
The US has been one of Kyiv’s strongest supporters since Moscow’s annexation of Crimea in 2014
