In all suits now pending in the United States Court of Federal Claims by an Indian tribe or band which have not been tried or submitted, and in any suit hereafter filed in the United States Court of Federal Claims by any such tribe or band, the United States Court of Federal Claims is directed to consider and to offset against any amount found due the said tribe or band all sums expended gratuitously by the United States for the benefit of the said tribe or band; and in all cases now pending or hereafter filed in the United States Court of Federal Claims in which an Indian tribe or band is party plaintiff, wherein the duty of the court is merely to report its findings of fact and conclusions to Congress, the said United States Court of Federal Claims is directed to include in its report a statement of the amount of money which has been expended by the United States gratuitously for the benefit of the said tribe or band: Provided