Ukrainian forces have faced dense minefields while carrying out counteroffensive operations. It has forced Ukrainian units to move slowly on foot rather than using tanks or other vehicles. Ukrainian officials are now calling for F-16 jets and more mine-clearance equipment.Ukraine has been forced to change its counteroffensive strategy after repeatedly coming up against dense Russian minefields, a report says.Ukrainian units are leaving behind the battle tanks and infantry fighting vehicles donated by Western allies and advancing slowly on foot, The Washington Post reported."You can no longer do anything with just a tank with some armor because the minefield is too...