Russia's foreign minister, Sergei Lavrov, has said negotiations taking place in Minsk to resolve the crisis in eastern Ukraine should seek an immediate ceasefire.
"They must leave positions from which they can harm the civilian population," Lavrov told students in Moscow yesterday. "I very much count on today's negotiations being devoted above all to the task of agreeing an immediate ceasefire, without conditions."
Meanwhile, Ukraine's defence minister warned yesterday that a "great war" had broken out with Russia over his country's future that could claim tens of thousands of lives.
"A great war has arrived at our doorstep -- the likes of which Europe has not seen since World War II. Unfortunately, the losses in such a war will be measured not in the hundreds but thousands and tens of thousands," Valeriy Geletey wrote in a Facebook post.
Russia again denied yesterday either sending or planning to send troops into eastern Ukraine to help separatist rebels pursue their recent counteroffensive against the pro-Western government's forces.
But insurgency leaders have admitted that some off-duty Russian soldiers had already joined their ranks.
NATO has also accused the Kremlin of advancing more than a 1,000 soldiers and heavy weapons across the Ukrainian border in recent days.
The Ukrainian president, Petro Poroshenko, accused Moscow of "direct and open" aggression against his country, as forces battled a Russian tank battalion for a vital airport in Luhansk yesterday, and in Ilovaysk, near the east's main city of Donetsk, several hundred Ukrainian forces remained trapped within an encirclement by Russia-backed separatists.
The talks in the Belarusian capital will bring together representatives of Russia, Ukraine, the Organisation for Security and Co-operation in Europe security forum and separatist rebels in eastern Ukraine.
Vladimir Putin has called on Kiev to enter discussions on "statehood" for the south-east regions of Ukraine a day after the EU gave Russia a week to de-escalate the situation in Ukraine or face further sanctions.
regions of Ukraine a day after the EU gave Russia a week to de-escalate the situation in Ukraine or face further sanctions.