Ukrainian forces have begun "shaping" operations in southern Ukraine to prepare the battlefield for a significant Ukrainian counteroffensive, two senior US officials briefed on the intelligence told CNN. Shaping operations are standard military practice prior to an offensive and involve striking weapons systems, command and control, ammunition depots and other targets to prepare the battlefield for planned advances. The US believes the Ukrainian counteroffensive, which has long been anticipated, will include a combination of air and ground operations. Ukraine indicated Monday morning that the actions were underway.