"I am honoured to be here today, next to our military," Zelenskiy he wrote in a post on the Telegram messaging app that was accompanied by footage of him handing out medals to troops in the Zaporizhzhia region.
In separate trips last week, Zelenskiy met soldiers in eastern Ukraine near the small city of Bakhmut - where fighting is intense - and spoke to officials and residents in the southern region of Kherson, where Ukrainian forces pushed back Russian troops last year after months of occupation.
Ukraine's ground forces commander said on Monday they were planning their next move after Russia shifted the focus of its offensive from a flagging assault on Bakhmut to the town of Avdiivka further south.
"I am thankful to each of our warriors for defending Ukraine, our sovereignty, our cities, and our children," Zelenskiy wrote on Telegram.
"We will definitely win."
In separate posts, Zelenskiy also released footage of himself visiting a command centre and meeting regional civilian and military officials.
"We are working and keeping all important issues under control," he wrote.
United Nations nuclear watchdog chief Rafael Grossi said on Monday he had met with Zelenskiy in Zaporizhzhia, the site of Europe's largest nuclear power plant.
The two had a "rich exchange" on the protection of the plant and its staff, Grossi wrote in a tweet.
He added that he reiterated the IAEA's full support for Ukraine's nuclear facilities.
Grossi, who is director-general of the Vienna-based International Atomic Energy Agency, plans to visit the Zaporizhzhia plant - which is held by Russian forces - this week.
The IAEA has staff permanently deployed at the plant following Russia's invasion 13 months ago.
Ihor Syrota, director general of the state-run Ukrhydroenergo hydropower generating company, told Reuters there was no immediate danger to the plant but that Ukraine feared it could face a shortage of water to cool reactors by late northern hemisphere summer.
The Zaporizhzhia plant, which continues to power war-torn Ukraine, has lost several of its power transmission cables during Russia's war and on multiple occasions has had to switch to emergency diesel generators to power its essential cooling systems preventing a meltdown.
In the meeting on Monday, Grossi said the situation at the plant remains tense because of the heavy military presence around it and a blackout that recently struck the facility, something that has occurred repeatedly since Russian forces took it over last year.
Earlier this month, fighting interrupted power supply to the plant for half a day, forcing staff to activate back-up generators.
Grossi expressed alarm at that development.
"Each time we are rolling a dice," he told his agency at the time.
"And if we allow this to continue time after time, then one day our luck will run out."
Grossi and Zelenskiy met in the the city of Zaporizhzhia, which is in Ukrainian-held territory, about 50km northeast of the nuclear plant with the same name.
with AP
