Ukraine said Friday that more must be done to ease tensions in the eastern part of the country after Russia withdrew its troops following a military buildup on its side of the border.

Ukrainian Foreign Minister Dmytro Kuleba said in a statement that the troop drawdown was welcome but did little to curb ongoing violence between Ukraines military and pro-Russia separatists in the Donbass region.

If Russia really pulls back from the border with Ukraine the enormous military force it has deployed there, this will already ease tensions. But we need to remember that this step would not put an end neither to the current escalation, nor to the conflict between Ukraine and Russia in general, Kuleba said.

The Ukrainian diplomat said Kiev still expects an explanation as to why Russia had to ramp up its military presence along the border and warned Western allies to not divert their attention away from the area, saying that further deterrence is needed against Moscow.

Russia still owes an explanation to Ukraine and international community of why it really needed to bring such numerous forces equipped with some offensive weapons at the border with Ukraine in such excessive number of troops, he said. 

Ukraine is grateful to our international partners for their resolute and timely reaction to Russias escalation. This has helped motivate Russia to take the decision to end its unprecedentedly dangerous exercises,” he added. “Ukraine calls on our partners to not lose vigilance for now, keep closely monitoring the situation and take further active steps to deter Russia. 

Kulebas comments come as international powers look to reduce tensions between Kiev and Moscow over concerns about the military buildup. At the height of the Russian military presence at the border, Moscow had the most troops in the area since 2014 when it invaded and annexed the Crimean Peninsula, raising fears that another invasion was imminent. 

The U.S. last week slapped a slew of sanctions on Russia over its malign behavior, including election meddling and its actions in Ukraine, and expelled 10 Russian diplomats. The U.K. also summoned the Russian ambassador in London, and Ukrainian President Volodymyr Zelensky met last week with the leaders of France and Germany to discuss the situation.