Ukrainian President Volodymyr Zelensky said he was visiting "advanced positions" of Ukraine's special forces near the hotspot of Bakhmut as Kyiv ramps up its counter-offensive.
"The Bakhmut direction, advanced positions of the Special Operations Forces," Mr Zelensky said on messaging app Telegram.
"I am here to congratulate our warriors on their professional day, to honour their strength."
Mr Zelensky said he was not at liberty to disclose details of the special forces' current operations.
He said he heard a commander's report and spoke with the troops, praising their "truly heroic" performance.
Ukraine last month began its highly anticipated fightback after stockpiling Western weapons and building up its offensive forces.
Kyiv has however admitted difficult battles and called on the United States and other allies to provide long-range weapons and artillery.
Ukrainian authorities have said Kyiv's troops are gradually moving forward near the eastern city of Bakhmut, which Russian forces seized in May.
Elsewhere, a Russian missile struck an apartment block in the central Ukrainian city of Dnipro yesterday, Kyiv officials said, injuring at least nine people including two children.
"Dnipro. Another terrorist attack," said Sergiy Kruk, head of the Ukrainian State Emergency Service, on Telegram.
"Currently, we know of nine injured, including two children. Work continues."
Internal Affairs Minister Igor Klymenko earlier reported "a Russian strike on a multi-storey building in Dnipro", saying five people had been injured.
Russia reported that it struck a military command post in the attack.
Videos posted on social media showed smoke billowing from the top floors of a residential building that had been badly damaged.
President Zelensky said: "Dnipro. Friday evening. A high-rise building and the Security Service of Ukraine's building were hit. Russian missile terror again".
"All necessary services are on site... We keep the situation under control. We will do everything to bring Russia to full punishment for aggression and terror against our people."
Russia said yesterday it intercepted two Ukrainian missiles over its southern Rostov region, bordering Ukraine.
It said at least a dozen people were wounded by debris falling on the city of Taganrog.
Russian regions bordering Ukraine have seen regular drone strikes and shelling since Moscow launched its military campaign in February last year but have hardly ever been targeted by missiles.
Elsewhere, the Financial Times has reported that Ukrainian soldiers were observed using North Korean rockets that they said were seized by a "friendly" country before being delivered to Ukraine.
Ukraine's defence ministry suggested the arms were captured from the Russians, the newspaper said.
The US has accused North Korea of providing arms to Russia, including alleged shipments by sea, but has not offered proof and North Korean weapons have not been widely observed on the battlefields in Ukraine.
North Korea and Russia deny conducting arms transactions.
The North Korean weapons were shown by Ukrainian troops operating Soviet-era Grad multiple-launch rocket systems near Bakhmut.
