137.3—Effect on existing Tribal rights.
         Nothing in this part shall be construed as:
    
    
        
        (a) 
         Affecting, modifying, diminishing, or otherwise impairing the sovereign immunity from suit enjoyed by Indian Tribes;
    
    
        
        (b) 
         Terminating, waiving, modifying, or reducing the trust responsibility of the United States to the Indian Tribe(s) or individual Indians. The Secretary must act in good faith in upholding this trust responsibility;
    
    
    
        
        (d) 
         Impeding awards by other Departments and agencies of the United States to Indian Tribes to administer Indian programs under any other applicable law.