During his visit, Mr Zelensky thanked troops who took part in the counter-attack against Russian occupiers.
He oversaw a flag-raising ceremony and said the Ukrainian flag would return to every city and village in the country.Ukrainian officials say they are targeting towns in the eastern Donbas region after making a series of gains in a rapid counter-offensive.
In a late evening address on Tuesday, Mr Zelensky said his forces were fortifying their hold over 8,000 sq km (3,088 sq miles) of retaken territory in the Kharkiv region.
