Ukraine's President Volodymyr Zelenskiy presented the new joint forces commander on Wednesday to troops defending the eastern frontline region of Donetsk.

Zelenskiy announced on Monday he was appointing Brigadier-General Andriy Hnatov to the post, which involves strategic planning of operations, replacing Lieutenant-General Yuri Sodol who had faced criticism over serious military setbacks.

Hnatov's main tasks include "preserving as many fighters' lives as possible" while repelling the invading Russian forces, Zelenskiy said in a video address posted on social media.

One of his meetings during the trip addressed security and support for the people of the Donetsk region, including water provision, social issues and evacuation, Zelenskiy said on the Telegram messaging app.

Zelenskiy recorded the video address against the backdrop of a city sign of Pokrovsk, along part of the front that has seen some of the most intense fighting during Russia's 28-month-long full-scale invasion.

In the video, he expressed surprise that some relevant government officials had not visited the region in six months or more.

"There will be a separate conversation in Kyiv, particularly with officials who must be here and in other areas near the frontline – in difficult communities where people need immediate solutions," Zelenskiy said. "Solutions that simply cannot be seen from Kyiv."

Zelenskiy and his army chief Oleksandr Syrskyi also listened to reports from frontline positions.

Ukraine's military has found itself on the back foot this spring as Russian forces opened a new front in the northeastern region of Kharkiv in May and continued to press Ukrainian forces in other directions. (Reporting by Anastasiia Malenko Editing by Peter Graff and Gareth Jones)