President Volodymyr Zelensky Wednesday visited military positions near the frontline town of Bakhmut in eastern Ukraine, the scene of the longest and bloodiest battle since the start of the Russia-Ukraine war, he said.

"Donetsk region. The frontline positions of the Ukrainian military in the Bakhmut area," Zelensky wrote on social media in English.

"I am honored to be here today to award our heroes. To shake hands and thank them for protecting the sovereignty of our country."

Video released by Zelensky's office showed the Ukrainian leader meeting servicemen in a warehouse and handing out awards.

Russian and Ukrainian forces have invested heavily in the battle for Bakhmut, even though analysts say the city carries little strategic value.

Kyiv says the battle for the industrial town, which had a pre-war population of around 80,000 people, is "key to holding back Russian forces along the entire eastern front."

Yevgeny Prigozhin, the head of Russia's Wagner mercenary group said this week his forces control some 70 percent of Bakhmut.