Britain's government on Saturday described mixed progress for Ukrainian and Russian forces fighting in southern and eastern Ukraine over the past 48 hours.
"In some areas, Ukrainian forces have likely made good progress and penetrated the first line of Russian defenses. In others, Ukrainian progress has been slower," Britain's Ministry of Defense said in a statement.
"Russian performance has been mixed: some units are likely conducting credible maneuver defense operations while others have pulled back in some disorder, amid increased reports of Russian casualties as they withdraw through their own minefields."