The bombardment, which Ukrainian officials said mostly targeted Kyiv, came just a day before President Trump was expected to talk with President Vladimir V. Putin of Russia.

The strikes – and renewed offer from the Vatican – come hours after Moscow and Kyiv had held their first direct peace talks in years that failed to yield a ceasefire.

Ukrainian President Volodymyr Zelenskyy announced that Ukraine was ready to accept a U.S. proposal for a 30-day cease-fire, provided Russia did the same.