KYIV, Ukraine — Ukraine’s president, Volodymyr Zelensky, made a rare and defiant trip near the front line on Wednesday, personally thanking soldiers who have been fighting in the devastated eastern city of Bakhmut, which has become a potent symbol of Ukrainian resistance.
The trip to the Bakhmut area came on a day when air- and seaborne drones attacked the Russian-occupied peninsula of Crimea and a Russian missile ripped into a nine-story apartment complex in Zaporizhzhia, in the south, killing at least one person and injuring more than 30 others.
At least seven other people were killed, including an ambulance driver, and nine others wounded when a drone strike hit a college in Rzhyshchiv, about 50 miles southeast of the capital, Kyiv, military officials said on Wednesday. The top floors of two dormitory buildings and another building were destroyed, according to Ukraine’s state emergency service.
Mr. Zelensky’s visit came as he and Russia’s president, Vladimir V. Putin, solidified alliances and secured help for the fight ahead when both sides are expected to mount offensives. China will continue to serve as a counterweight to Western sanctions imposed on Russia, and Ukraine’s allies promised more and faster help, including a $15.6 billion loan from the International Monetary Fund.
Mr. Zelensky condemned Russia’s attack in Zaporizhzhia, saying that Mr. Putin’s forces were once again targeting civilians, a tactic that has prompted accusations of war crimes against Moscow.
“Right now, residential areas where ordinary people and children live are being fired at,” Mr. Zelensky wrote on Twitter, showing a video of a large explosion tearing into a high-rise apartment building. “This must not become ‘just another day’ in Ukraine or anywhere else in the world.”
Later, in his nightly speech, the Ukrainian leader promised retaliation, saying, “All Russian strikes will receive a military, political and legal response.” He also said he had visited Kharkiv, north of Bakhmut, on Wednesday to discuss reconstruction efforts, restoring electricity and removing land mines.
“Kharkiv gives strength to our entire east,” he said.
In Crimea, the Russia-appointed governor, Mikhail Razvozhaev, said after that attack that three drones had been destroyed and that Russian ships were undamaged. It was the second straight day that drones were reported to have targeted the peninsula. It was not clear who was behind the drones. Ukraine rarely takes responsibility for attacks in territory claimed by Russia.
Mr. Zelensky, who last visited Bakhmut publicly in December, has said that he and his generals are determined to hold on to the city in Ukraine’s Donbas region despite Russia’s efforts to encircle it. He argues that the monthslong fight is wearing down Moscow’s forces and resources.
On this trip, he shook soldiers’ hands and thanked them for their bravery.
“Thank you for protecting the state, sovereignty, the east of Ukraine,” Mr. Zelensky said, according to a statement from his office that included images showing him posing for selfies with troops. It did not give his exact location, but an image posted on Twitter by OKKO, a Ukrainian gas station chain, showed Mr. Zelensky with staff members at a branch in Kostyantynivka, about 15 miles from Bakhmut.
In his nightly speech, he said it was “distressing” to see the “suffering and ruin” in the eastern Donbas region.
“Wherever Russian evil has come, it is obvious that the terrorist state cannot be stopped by anything other than one thing — our victory,” he said. “And we will ensure it — the Ukrainian victory.”
The battle for Bakhmut, which began in the summer, has become one of Russia’s longest-running assaults since its full-scale invasion more than a year ago. The fighting has intensified in recent months, with Moscow throwing thousands of men from its armed forces and the Wagner private military company into a grinding and often block-by-block battle that has produced heavy casualties for both sides.
The battle has also consumed a huge amount of Kyiv’s ammunition supplies, leading some Western and Ukrainian officials to warn that trying to hold Bakhmut, whose strategic significance is debated, could weaken Kyiv before the anticipated spring offensive.
Mr. Zelensky’s visit came days after Mr. Putin visited the southern Ukrainian city of Mariupol, now occupied by Russian forces after one of Moscow’s most brutal campaigns of the war.
The trip to Mariupol, about 50 miles southeast of the Ukrainian-controlled town of Vuhledar — where Russian forces sustained heavy losses just weeks ago and where fighting continues — is believed to be the closest Mr. Putin has come to the front line since the Russian invasion.
More than a year of fighting has left much of Ukraine in ruins, and the I.M.F. and Ukraine reached a preliminary agreement on the loan to help the country close staggering budget deficits and recover from widespread damage to its infrastructure.
The United States and European nations pushed for the package, and the fund’s board is expected to review the four-year program in the coming weeks, according to a statement released on Tuesday.
Marc Santora reported from Kyiv, Ukraine; Valerie Hopkins from Berlin; and Victoria Kim from Seoul.
