A 2015 agreement to bring peace to Ukraine’s volatile east remains largely unimplemented and civilians are paying the highest price, with more than 3,300 killed and 3.5 million needing humanitarian aid this year, U.N. officials said Tuesday.

Russia’s annexation of the Crimean Peninsula in early 2014 and support for separatist rebels in the east triggered a conflict with Ukrainian government forces that the U.N. says has also injured up to 9,000 civilians and displaced 1.5 million people.

Assistant Secretary-General Miroslav Jenca told the Security Council that negotiations “appear to have lost momentum,” with Russia and Ukraine unable or unwilling to agree on key steps forward or too distracted to focus on implementing the 2015 agreement.

Russian Ambassador Vassily Nebenzia and Ukrainian Ambassador Volodymyr Yelchenko blamed each other for the failure to implement the agreement signed in the Belarus capital, Minsk.

Jenca, who is in charge of European affairs, stressed that the conflict in eastern Ukraine is not dormant. “It is a conflict in the heart of Europe which continues to claim victims,” he said.

Jenca said the main parties have committed to over a dozen cease-fires since the start of the conflict, but “each one was regrettably, short-lived.”

The Organization for Security and Cooperation’s monitoring mission in Ukraine reports that the military positions of both sides are coming closer to each other in the “gray areas” near the so-called “contact line,” he said. “The use of heavy weapons and their deployment in the proximity of the contact line is a reality.”

Ursula Mueller, the U.N.’s deputy humanitarian chief, said the conflict is causing severe humanitarian problems, noting that many of the 3.5 million people who need aid are elderly, women and children.

“Many are struggling to access schools, hospitals and other essential services,” she said. “Many have lost their jobs, homes, family members and friends.”

Mueller said the U.N. has appealed for $162 million this year to aid 2.3 million people.  

Ertugrul Apakan, chief of the OSCE monitoring mission in Ukraine, told the council by video that many people use checkpoints in eastern Donetsk and Luhansk to receive pensions and see families separated by the conflict. Since December, he said, there have been “14 cases of people who died from natural causes while waiting at the checkpoints.”

Mueller said most of those who died this year were elderly. People wait for several hours in freezing temperatures to cross the contact line, and she urged better conditions and additional crossing points, especially in Luhansk where there is only one.

Before the meeting, eight former and current European Union members of the Security Council issued a joint statement urging humanitarian access to areas not under Ukrainian government control.

They called on Russia “to immediately stop fueling the conflict by providing financial and military support” to the separatists and reiterated their opposition to Moscow’s annexation of Crimea. Nonetheless, they said, they “remain convinced that a peaceful resolution of the conflict is possible.”

Nebenzia said Russia called the council meeting to discuss implementation of the 2015 agreement, declaring that the situation in southeastern Ukraine “remains explosive” with positions now “too close to each other at some locations.” He said Ukraine “comprehensively and consciously ignores and sabotages the Minsk agreements and our Western partners cover up for all of its unlawful acts.”

Ukraine’s Yelchenko countered that “it is only Russia and its ongoing military activity in the occupied territories of the Donetsk and Luhansk regions of Ukraine as well as in Crimea that constitute for now an unsurmountable obstacle for the peaceful resolution of the conflict.”