Russian and Ukrainian officials agreed to a temporary cease-fire in the besieged southern port city of Mariupol, with evacuations planned for Friday, even as the Pentagon reported devastating airstrikes there and in Kyiv, the capital, over the previous 24 hours.

Dozens of buses began arriving in the area around Mariupol on Thursday to deliver humanitarian aid and transport civilians, an effort that a spokesman for the International Committee of the Red Cross called “desperately important” for a city that has borne the worst of Russia’s invasion and where 100,000 residents may still be trapped…

A senior U.S. defense official, speaking on the condition of anonymity under ground rules set by the Pentagon, said Moscow could be planning to seize Mariupol as a springboard into the eastern Donbas region, where Russians troops may try to envelop Ukrainian forces. Russia’s military has increasingly tried to seize towns in that part of Ukraine, the Pentagon has said, and forces pulled from the country’s north appear to be heading there.