Ukrainian President Petro Poroshenko vowed to hold a referendum on NATO membership amid renewed tensions with Russia.

"As the president, I act in accordance with the views of my people, and I will hold a referendum on the question of NATO membership," Poroshenko said in an interview with German daily Berliner Morgenpost. "And if the Ukrainians would vote for it, I will do everything in my power to achieve membership in the transatlantic alliance," he added.

Poroshenko's remarks came amid a new outburst of fighting between government troops and pro-Russian separatists in eastern Ukraine.

Russia had long opposed Ukraine's NATO membership bid and viewed continued eastward expansion of the alliance as a potential military threat.

Poroshenko did not give a date for a referendum, but underlined that support for NATO membership among the Ukrainian citizens had grown in recent years. "Four years ago, almost 16 percent supported Ukraine's NATO membership. Now it is 54 percent," he said. NATO has recently intensified military cooperation with Ukraine, but refrained from offering a full membership perspective, largely due to reservations by key members, Germany and France. Ukraine has been wracked by conflict since April 2014, following Russia's annexation of Crimea from Ukraine. Fighting between Ukrainian government forces and pro-Russian separatists in eastern Ukraine has seen more than 9,600 killed, according to the UN.