Russian Strikes Hit Ukrainian Cities at a Tense Time for Kyiv

Missiles streaked into Kyiv early Wednesday in a Russian attack that killed at least five people, according to local officials, jolted residents awake with air alarms and explosions, and ignited a fire that sent plumes of smoke billowing over the Ukrainian capital.

The barrage, which directed missiles and drones at cities across the country, coincided with a moment of heightened uncertainty for Ukraine. Russian forces are pressing assaults in towns and villages along the front, American aid is in doubt, and President Volodymyr Zelensky of Ukraine is preparing for what he has hinted will be a major shake-up in his government and the army’s leadership.

Mr. Zelensky is considering replacing Gen. Valery Zaluzhny, the country’s top military commander, but has not announced any decision on the matter. General Zaluzhny remains in his job and said on Wednesday morning that Ukrainian air defense teams had destroyed 44 of the 64 cruise missiles, ballistic missiles and drones that Russia had fired in the assault.

Since the end of last year, Russia has stepped up its large-scale aerial bombardments in a bid to exploit dwindling supplies of critical Western air defense munitions and inflict maximum damage.

“Ukraine needs help,” Andriy Yermak, the head of the Ukrainian president’s office, said in a statement. “Only the joint efforts of the democracies will stop the criminal Putin.”

A broad measure that would allow American arms to flow to Ukraine once again is expected to fail in a Senate vote on Wednesday amid growing Republican opposition and deep division on Capitol Hill.

Since Russia’s full-scale invasion in early 2022, the United States has provided about half of the foreign military assistance to Ukraine’s arsenal. European nations lack American-level stockpiles of weapons and ammunition and would be unlikely to fill the gap, military analysts say.

The dwindling level of aid is affecting Ukraine on the battlefield. Its soldiers are struggling to stem relentless Russian assaults in eastern Ukraine, and the attacks by Russia, which has an advantage in artillery and personnel, are whittling away at Ukraine’s defenses.

“Ukraine could effectively hold for some part of this year” without more American military aid, Michael Kofman, a Russia expert at the Carnegie Endowment for International Peace in Washington, said in a telephone interview. “But over time there would be no prospect to rebuild the military, and they will start to lose slowly.”

The absence of further American help, he said, would “point to a dour, negative trajectory in the latter half of this year.”

The scope of the latest attacks by Russia on Ukraine was still coming into focus on Wednesday morning, but four people were killed in the capital and at least 32 others were injured, according to city officials.

As the Ukrainian Air Force warned that missiles were streaming toward Kyiv along the Dnipro River around 7 a.m., interceptor missiles streaked through the skies to meet the threat. Explosions echoed in the skies, and a residential building caught fire in the attack, sending plumes of black smoke over the city of more than three million during the morning rush hour.

Residents in one neighborhood temporarily lost power after debris hit a high-voltage cable, the local power provider, DTEK, said in a statement.

In the southern port city of Mykolaiv, airstrikes damaged more than 20 residential buildings, city officials said, and killed at least one person.

Missile attacks were also reported in the Kharkiv region of northeastern Ukraine, in Cherkasy in the center of the country, and in the Lviv region near the border with Poland.