The Secretary may, to the extent he deems appropriate, hold harmless or provide liability insurance for any person to whom the immunity provisions of subsection (a) of this section apply, for damages for personal injury, including death, negligently caused by any such person while acting within the scope of his or her office or employment and as a result of the furnishing of medical care or related services, including the conducting of clinical studies or investigations, if such person is assigned to a foreign area or detailed for service with other than a Federal agency or institution, or if the circumstances are such as are likely to preclude the remedies of third persons against the United States provided by sections
1346
(b) and
2672 of title
28, for such damage or injury.