In case of an overstatement by any war contractor of the amount due on his termination claim or claims in connection with any interim financing under this chapter, such contractor shall pay to the United States, as a penalty, an amount equal to 6 per centum of the amount of the overstatement, but the Administrator of General Services may suspend or modify any such penalty if in his opinion the imposition thereof would be inequitable. Any penalty may be deducted from any amounts due the war contractor upon such termination claim or claims, or otherwise, or may be collected from the war contractor by suit. The obligation to pay any penalty imposed and to repay any interim financing made or assumed by the United States under this chapter shall constitute a debt due to the United States within the meaning of section
3713
(a) of title
31.