The new figure represents an ominous turning point in the battle between Ukrainian troops and pro-Russian separatists that was supposed to have halted under a September ceasefire agreement.
The conflict as a whole has now taken more than 5,300 lives, roughly 2,000 of them since the ceasefire.
The past few weeks have been marked by a surge in deadly attacks, including bus bombings, the capture of the Donetsk airport by the rebels, and indiscriminate shelling.
Now the White House is reportedly considering sending lethal aid to Ukraine.
"What's being discussed is perhaps we should begin providing defensive weapons, defensive equipment, to Ukraine," a senior U.S. official told Agence France-Presse on Monday.
Lawmakers on both sides of the aisle have urged the president to send arms in recent months.
Days before the September ceasefire, as Russian troops were seen streaming across the Ukrainian border, Democrats put pressure on the president to send lethal aid to Ukraine.
In November, shortly after the Republicans captured the Senate, Senators John McCain and Lindsey Graham renewed their call to "provide Ukraine with the arms and related military and intelligence support that its leaders have consistently sought and desperately need."
For his part, Ukrainian President Petro Poroshenko also addressed a session of Congress in September during which he practically begged the United States to provide weapons, stressing that “blankets, night-vision goggles are also important. … But one cannot win the war with blankets. Even more, we cannot keep the peace with a blanket. ... In Ukraine, you don’t build a democracy. It already exists. You just defend it.”
The shift in the White House's openness about lethal aid accompanies the prospect of more violence.
On Monday, as The Wall Street Journal reported, the leader of the Russian-backed rebel separatists announced plans "to raise up to 100,000 troops to fight in eastern Ukraine."
The report added: "The announcement comes as Kiev is enlarging its own army through a new round of conscriptions."
On Tuesday, separatists reportedly downed another Ukrainian jet.
A few things have kept the White House from sending arms to Ukraine⎯the crippling sanctions already in place against Russia, the White House's semi-aversion to foreign entanglements, and, most saliently, the question of whether American arms will inflame the situation.
"Russia is not ready to back down and it can match the U.S.,” one expert told Bloomberg.
The New York Times noted that the president's thinking may have been swayed by a report submitted by eight former high-ranking officials.
The authors proposed sending $3 billion in weapons and equipment to provide Ukraine with enough retaliatory power that, in the report's words, "Moscow will deterred from further aggression."
Another question is whether American allies would offer support for a policy shift or even send weapons of their own.
A leading U.S. partner responded right away; on Tuesday, German Chancellor Angela Merkel reiterated her preference for enhancing sanctions against Russia instead of sending arms.
"Germany will not send Ukraine any deadly, lethal weapons, as I said yesterday," Merkel told a news conference.
"We are focusing on a diplomatic solution and the foreign ministers have made clear that if the situation gets even worse ... then it will be necessary to work on further sanctions."
Source: The Atlantic