KYIV, Ukraine — Ukrainian fighters holed up in a steel plant in the last known pocket of resistance inside the shattered city of Mariupol have ignored a surrender-or-die ultimatum from the Russians and continue to hold out against the capture of the strategically vital port.
Mariupol has been the site of a merciless, 7-week-old siege that has reduced much of the city to a smoking ruin.
Its fall would be Moscow's biggest victory of the war yet and free up troops to take part in a potentially climactic battle for control of Ukraine's industrial east.
