A claim under section
1645b of this title based upon an ownership interest in any corporation, association, or other entity which is a national of the United States may not be considered. A claim under section
1645b of this title based upon a debt or other obligation owing by any corporation, association, or other entity organized under the laws of the United States, or of any State, the District of Columbia, or the Commonwealth of Puerto Rico may be considered only if such debt or other obligation is a charge on property which has been nationalized, expropriated, or otherwise taken by Vietnam.