President Volodymyr Zelensky on Tuesday invited Russian leader Vladimir Putin to meet in war-torn eastern Ukraine, stressing that millions of lives were at stake from fresh fighting in the separatist conflict.

The blunt offer for talks came following a flare-up in clashes between Ukraine's army and pro-Russian separatists controlling two regions in the country's east, raising concerns of a major escalation in the simmering war.

Map of Ukraine locating regions under separatist control and the Crimea, annexed by Russia.
Map of Ukraine locating regions under separatist control and the Crimea, annexed by Russia. AFP / Jochen GEBAUER

In an address to the nation, Zelensky said that Ukrainian and Russian negotiators had recently discussed plans for officials to travel to the frontlines of the trench conflict to assess the situation.

"I am ready to go even further and invite you to meet in any part of the Ukrainian Donbass where war is ongoing," Zelensky said.

Fighting between the two sides has escalated recently
Fighting between the two sides has escalated recently AFP / STR

The Ukrainian president, elected in 2019 on promises to bring an end the conflict, accused Russia of participating in peace negotiations while massing troops on Ukraine's border.

"A considerable number of Russian troops are concentrated near our border," he said. "Officially, Russia calls this military exercises. Unofficially, the whole world calls this blackmail.

"The Russian president once said that if a fight is inevitable, you need to hit first. But every leader needs to understand that a fight must not be inevitable when it... concerns a real war and millions of human lives."

A Ukrainian serviceman stands on the frontline with Russian-backed seperatists in the Donetsk region
A Ukrainian serviceman stands on the frontline with Russian-backed seperatists in the Donetsk region AFP / Aleksey Filippov

Ukraine, the European Union and the United States have recently sounded the alarm over renewed tensions and accused Russia of massing tens of thousands of military personnel on the northern and eastern borders of the ex-Soviet country.

The EU on Monday estimated the number of Russian troops along the Ukrainian border at more than 100,000 during talks with Ukraine's foreign minister, who encouraged Western countries to hit Russia with a deeper package of economic sanctions over the conflict.

Ukrainian forces take part in a tank drill in Donbass region amid the largest deployment of Russian troops on Ukraine's borders since 2014
Ukrainian forces take part in a tank drill in Donbass region amid the largest deployment of Russian troops on Ukraine's borders since 2014 Armed Forces of Ukraine / Handout

Kiev has been battling pro-Russian separatists in the eastern Donetsk and Lugansk regions since 2014, following Moscow's annexation of the Crimean peninsula -- a move that plunged Russia's ties with the West to new lows and led to economic penalties.

Russian tank units hold drills in Crimea. In recent weeks, Russia's massing of troops on Ukraine's northern and eastern borders, and on the Crimean peninsula it annexed seven years ago, have contributed to a sharp escalation in tensions.
Russian tank units hold drills in Crimea. In recent weeks, Russia's massing of troops on Ukraine's northern and eastern borders, and on the Crimean peninsula it annexed seven years ago, have contributed to a sharp escalation in tensions. MINISTERE RUSSE DE LA DEFENSE

The conflict, which has claimed more than 13,000 lives, has seen 30 Ukrainian soldiers killed since the start of the year, compared to 50 in all of 2020.

The escalation along the frontline as well as sharp rhetoric has spurred fresh rounds of talks. Ukrainian and Russian negotiators met earlier this week and also on Tuesday, although they have so far failed to secure any breakthroughs.

Zelensky said in his address to the nation that although Ukraine did not want war, it was prepared to fight.

"Will Ukraine defend itself if something happens? Always. Our principle is simple: Ukraine does not start a war first, but Ukraine always stands to the last," he said.

On the frontline however, fears were growing of a major escalation, with soldiers set to repel attacks and streets in towns near the front line empty over fears of a return to war.

Yuliya Yevchenko, 27, who lives in a partially destroyed residential building in Krasnogorivka under government control said the sounds of loud shelling could be heard recently in the town just kilometres from the frontline.

"We had a truce, and now it is war again," the mother of four said, holding her one-year-old son in her arms.

"I don't know what to do. We have nowhere to go at the moment."

Faced with the largest deployment of Russian troops on Ukraine's borders since 2014, Zelensky has requested help from the West.

"The world says it wants to help Ukraine," Taras, a 24-year-old soldier, told AFP in the frontline village of Mariinka west of the separatist stronghold Donetsk.

"But for now, we are fighting against Russia on our own."