Ukrainian President Volodymyr Zelenskiy says he has called his Russian counterpart, Vladimir Putin, to urge him to help halt fighting in eastern Ukraine, following the killing of four soldiers there.
"I called him urgently. I told him that this brings us no closer to peace," Zelenskiy said during a news briefing in Kyiv, adding that he had urged Putin to ask the Moscow-backed separatists who are holding parts of eastern Ukraine to "stop killing our people."
He also said Putin had promised him something, details of which would be disclosed later.
The Kremlin said the two presidents discussed the prospects of cooperation under the so-called Normandy format for negotiations aimed at putting an end to the conflict, and agreed to intensify their work on prisoner exchange.
It was their second publicly announced phone call since Zelenskiy was elected president in April.
Later in the day, the Ukrainian president said he had also spoken with French President Emmanuel Macron, and that his French counterpart had supported his call for a new round of talks within the Normandy format, which involves France, Germany, Ukraine, and Russia.
Fighting between Ukrainian forces and the separatists who control parts of the eastern Donetsk and Luhansk regions has killed more than 13,000 people since April 2014.
On August 6, Ukraine said four of its soldiers had lost their lives in clashes in the Donetsk region, the highest daily casualty toll in the Ukrainian conflict since a truce was agreed nearly three weeks ago.
The separatists opened fire at Ukrainian military positions, using grenade-launchers, machine guns, and assault rifles, the Defense Ministry said.
Cease-fire road maps announced as part of the Minsk accords -- September 2014 and February 2015 pacts -- have contributed to a decrease in fighting but have failed to hold.
A new truce agreement was supposed to go into effect on July 22.