Churchill felt well pleased with these negotiations and said as much when he contacted Roosevelt on the 27th. The previous day, however, Rommel had launched his counter-offensive, "Operation Venice", to begin the Battle of Gazala. The Allies were ultimately driven out of Libya and suffered a major defeat in the loss of Tobruk on 21 June. Churchill was with Roosevelt when the news of Tobruk reached him. He was shocked by the surrender of 35,000 troops which was, apart from Singapore, "the heaviest blow" he received in the war. The Axis advance was eventually halted at the battles of El Alamein (first battle; July) and Alam el Halfa (early September). Both sides were exhausted and in urgent need of reinforcements and supplies.