Denis Pushlin, who heads the self-proclaimed People's Republic of Donetsk, called for "all men able to hold a rifle to come to the defense of their land."
Russian-separatist forces attacked Ukrainian positions more than 50 times on February 1 alone.
$3 billion is chump change for Putin, but payment could drive Ukraine into an acute currency crisis.
A vote on more autonomy for the eastern regions occupied by pro-Russian forces sparks violence.
Members of the battle-hardened Azov battalion are feeling sidelined.
Russian-backed artillery bombardment of Sartana, Ukraine, spurs the mayor to visit the library for inspiration.
'The notion that there is, or ever was, a cease-fire in eastern Ukraine is a farce.'
Putin-backed forces appear to be trying to encircle the city, which stands on the road to Crimea.
The pro-Russian separatists have access to a radioactive bunker. Kiev fears they plan to weaponize it.
Russian TV has been exaggerating small separatist protests to suggest that Ukraine is disintegrating.
Donetsk rebels have dismissed the president's proposal as "Kiev trickery."
By deeming the old Soviet Union's ceding of the Baltics and Ukraine illegal, Putin hopes to unsettle Europe.
Combined Russian-separatist forces have withdrawn from Shyrokyne. But Mariupol residents remain wary.
Russia's Foreign Ministry bans U.S. Vice reporter Simon Ostrovsky from working in Russia.
Attack puts pressure on G7 leaders meeting this weekend to tighten the sanctions against Putin and his oligarchs.
U.S. and Ukrainian official have both reported that both Russian troops and weaponry are gathering on the border.
Soldiers with untreated post-traumatic stress disorder are reportedly partly responsible, say NGOs.
Vaccination rates have fallen dramatically in the last few years, and the conflict is making things worse.
He aims to overthrow the entire post-Cold War order in Europe.
Former NATO chief urges U.S. to send "lethal aid" to Kiev.
The Russian president is struggling to please both hawks and doves in the Kremlin.
The military said a truce had been most fully observed around the rebel-controlled city of Luhansk and near government-held Mariupol on the Sea of Azov.
The ceasefire agreed in Minsk last week is now on the brink of total collapse as the rebels advance on Mariupol.