President Volodymyr Zelenskyy has arrived in the liberated Kharkiv town of Izyum.
A week ago, the city was still under Russian occupation.
The national flag was solemnly hoisted over the Izyum city council, the 25th Sicheslav Airborne Brigade reported on Facebook.
"The ceremony was attended by Ukrainian President Volodymyr Zelenskyy, Deputy Defence Minister Hanna Malyar, representatives of the Ukrainian Armed Forces and other security agencies who liberated the town from the ruscist occupiers a few days ago," the report reads.
The ceremony started with the commemoration of the fallen Ukrainian soldiers with a minute's silence, and the president thanked the troops for liberating the Ukrainian land.
Zelenskyy visited wounded soldiers in Lviv region last month, and before that he checked front-line positions near Bakhmut, Donetsk Region and in Zaporizhzhya Region.
Izyum was liberated during the Ukrainian Defence Forces' offensive in Kharkiv Region last week. On 10 September, the first footage of the Ukrainian Armed Forces entering the city emerged.
According to the city council, at least 1,000 civilians were killed by the Russian army. The city had been under occupation since April.