One missile hit a two-story building with eight apartments where emergency workers hunted for survivors Thursday morning. A five-story building next door lost all of its windows. People stood outside, staring at the damage and talking on their phones, telling loved ones that they were alive. No military target was visible nearby.

Mr. Zelensky said that nearly 70 missiles, including ballistic ones, and about 150 attack drones had targeted cities across the country — although Kyiv was the hardest hit.

“It is extremely important that everyone around the world sees and understands what is really happening,” he wrote in a social media post, adding that he would cut short a visit to South Africa and return to Ukraine after meeting the South African president.

The attack came hours after President Trump and his top aides demanded that Kyiv accept an American-designed plan that would seemingly grant Russia all of the territory it has gained in the war, which started with Russia’s full-scale invasion in February 2022. The plan also offers Kyiv only vague assurances about the country’s future security. So far, Mr. Zelensky has said Ukraine cannot accept such a deal.

Since taking office in January, the Trump administration has echoed Kremlin talking points in the war, a reversal of previous U.S. policy under the Biden administration. Over the past week, the Trump administration has repeatedly threatened to walk away from the peace process, claiming that the two sides were both intransigent. On Wednesday, planned peace talks in London were downgraded, largely because the United States decided not to attend.

Mr. Trump later called the Ukrainian president “inflammatory” in a post on social media and said Mr. Zelensky would only “prolong the ‘killing field.’”

“The president’s frustrated; his patience is running very thin,” Karoline Leavitt, the White House press secretary, told reporters later that day. But she echoed Mr. Trump in appearing to shift blame to Mr. Zelensky, saying that Mr. Trump sought peace but that Ukraine’s leader seemed to be “moving in the wrong direction.”

In his social media post on Thursday, Mr. Zelensky again pointed out that Ukraine had accepted a U.S. proposal for a 30-day cease-fire in March while President Vladimir V. Putin of Russia has refused to agree to that plan. A temporary truce announced by Mr. Putin for Easter Sunday seemed like more of a public relations stunt than an actual cease-fire along the front lines — but Ukrainian cities, at least, were largely spared for the truce’s 30 hours.

That was not the case early Thursday. Shortly after midnight, the first air alarms sounded.

Yevhenii Plakhotnikov, 40, who sells furniture, lives just across from the two-story apartment building struck by a missile. He said that he woke up to the alarm, heard the buzzing sound of drones and then started getting dressed. A message on Telegram — the messaging platform that many Ukrainians rely on for missile alerts — said a ballistic missile had been launched.

Mr. Plakhotnikov said he went to the hallway to put on his shoes.

“While I was putting on the second sneaker, I heard the first explosion,” he recalled in an interview. “Then I heard something heavy fall. All my interior doors were torn in half. I opened the door and saw shrapnel flying.”

He said he helped get other people out of his building. There, one man was standing, covered in blood. Another, standing a bit farther away, said merely: “That apartment building in the courtyard is gone.”

Emergency workers searched for survivors in the rubble. At 8:30 a.m. local time, an emergency service spokeswoman, Svitlana Vodolaha, told reporters: “Just now we dug out another person. Alive!”

Tetyana Hrynenko, 58, stood on the street, covering her mouth with her hands and looking up her ruined apartment next to the flattened building.

“The most important thing is that we are alive,” said Ms. Hrynenko, adding that she had heard two explosions, saw clouds of dust and smelled burning. She added: “I heard screams — ‘Help!’ — People were shouting and asking for help. I looked out into the stairwell, and there were no stairs. And I live on the fifth floor.”

Residents managed to clear the stairwell of rubble, allowing Ms. Hrynenko and others to make it outside.

Ukrainian officials have said that Russia has only intensified attacks against civilians since the start of U.S.-led peace negotiations.

Andriy Yermak, the Ukrainian president’s chief of staff, posted a video on social media showing emergency workers outside a destroyed building on Thursday. “Once again, Russia strikes civilians,” he said.

Other Ukrainian officials urged Western partners to replenish Kyiv’s air defenses. Ihor Klymenko, the minister of internal affairs, said that Ukraine lacked the air defense forces to shoot down a large number of missiles and drones.

In March, Mr. Trump had pledged to work with Mr. Zelensky to find U.S.-made Patriot air defense systems. But when Mr. Zelensky said this month that he wanted to buy Patriots from the United States, Mr. Trump suggested that Ukraine had “started the war” and said the Ukrainian president was “always looking to purchase missiles.”

Thursday’s attack on Kyiv was one of the deadliest of the war and the worst in the capital since July, when Russian missiles destroyed a children’s hospital in Kyiv and killed more than 20 people throughout the city. Recent deadly missile strikes have also targeted the cities of Sumy and Kryvyi Rih, inflicting large numbers of civilian casualties.

The authorities originally said that nine people had been killed in Kyiv on Thursday, but later lowered the number of confirmed fatalities to eight.

As search and rescue efforts continued hours after the attack on Thursday morning, those affected by the strike said that they want the war to end but could not see accepting a one-sided deal that would benefit Russia.

“Yesterday we were very disappointed that the negotiations hadn’t moved forward, and then overnight, it hit me directly,” said Ms. Hrynenko as she surveyed her damaged apartment. “I am disappointed. Exhausted.”

Mr. Plakhotnikov said he did not know of a way out for Ukraine.

“There’s no point in continuing the war,” he said, “but it’s also impossible to stop.”

Andrew E. Kramer contributed reporting from Kharkiv, Ukraine, and Oleksandra Mykolyshyn from Kyiv.