The insurance companies and other insurers which form, associate, or otherwise join together in the pool under this part may adjust and pay all claims for proved and approved losses covered by flood insurance in accordance with the provisions of this chapter and, upon the disallowance by any such company or other insurer of any such claim, or upon the refusal of the claimant to accept the amount allowed upon any such claim, the claimant, within one year after the date of mailing of notice of disallowance or partial disallowance of the claim, may institute an action on such claim against such company or other insurer in the United States district court for the district in which the insured property or the major part thereof shall have been situated, and original exclusive jurisdiction is hereby conferred upon such court to hear and determine such action without regard to the amount in controversy.