German Chancellor Angela Merkel called on Thursday for Russia to withdraw troops deployed along the Ukrainian border during a phone call with Vladimir Putin.
A transcript of the phone conversation from the German Chancellery said the two leaders discussed "the increased Russian military presence in the vicinity of eastern Ukraine."
"The Chancellor called for the reduction of these troops reinforcements in order to achieve a de-escalation of the situation," the statement said.
In its own transcript, the Kremlin made no mention of its troops stationed near the border but said President Putin "drew attention to the provocative actions of Kyiv which is now deliberately aggravating the situation along the line of contact."
"They urged the parties to the conflict to display restraint and to invigorate the negotiating process in order to fully implement the 2015 Minsk Package of Measures as the only legal foundation for a peace settlement," it added.
The conversation between Merkel and Putin comes as Ukrainian President Volodymyr Zelenskiy visited the country's east amid an escalation of tensions that have raised fear the conflict could erupt in large-scale hostilities once more.
"I want to be with our soldiers in the tough times in Donbas," he said on Twitter, adding that a 23-year-old soldier was killed on Wednesday.
Zelenskiy has accused Russia of flexing its military muscles and held a series of calls with Western leaders to rally support for Ukraine amid the tensions.
NATO chief Jens Stoltenberg said on Tuesday that he had discussed "Russia's military activities in and around Ukraine and ongoing ceasefire violations" and reaffirmed the alliance's support for "Ukraine's sovereignty and territorial integrity."
The European Union's top diplomat, Josep Borrell, said earlier this week he was "following with severe concern the Russian military activity surrounding Ukraine" and offered the bloc's "unwavering" support for Ukraine's sovereignty. He added that foreign ministers from the 27 member states would discuss the issue at their next meeting on April 19.
Russia has rejected the claims, arguing that it can deploy its troops wherever it deems necessary on its territory and emphasising that they don't threaten anyone. It has accused Ukrainian authorities of trying to stoke up tensions in the east for domestic policy purposes.
The conflict with Russia-backed separatists in eastern Ukraine erupted shortly after Moscow’s 2014 annexation of Ukraine’s Crimea peninsula. More than 14,000 people have died in the fighting.