President Petro Poroshenko on Monday called on Moscow to "immediately" cease "aggressive" actions in eastern Ukraine.
"The president called the last days of July some of the bloodiest in 2017 and urged Russia to immediately cease aggressive actions as well as the supply of weapons to the occupied territories," the presidency said in a statement.
Poroshenko's remarks came after a phone conversation with his Russian counterpart Vladimir Putin, France's Emmanuel Macron and chancellor of Germany, Angela Merkel.
According to the statement, the four leaders heard the report of the chief monitor of the Organization for Security and Co-operation in Europe (OSCE) Special Monitoring Mission to Ukraine Ertugrul Apakan and his deputy Alexander Hug.
They noted the importance of full cease-fire, withdrawal of heavy weaponry and troops, as well as 24/7 monitoring by the mission.
Poroshenko also emphasized the importance of the deployment of a UN peacekeeping mission in Donbass, in eastern Ukraine.
The leaders agreed to continue working on a roadmap for the Minsk agreement’s implementation.
"To that end, foreign policy advisors of the Heads of State of the Normandy format will meet in the second part of August," it added.
Ukraine has been wracked by conflict in its eastern regions since March 2014 after Russia’s annexation of Crimea. The fighting with separatists in the Donbass area has led to more than 10,000 deaths, according to the UN.