Neb. Rev. Stat. § 72-1257

In the event of default in the payment of principal of, or interest on, any investment made by the state investment officer, the State Treasurer may institute the proper proceedings to collect such matured principal or interest, and may, with the approval of the state investment officer, accept for exchange purposes refunding bonds or other evidences of indebtedness. The State Treasurer, with the approval of the state investment officer, may make such compromise, adjustment, or other disposition of the past-due interest or principal in default, or make such compromises, adjustments or other disposition as to future payments of interest or principal as deemed advisable to protect the money invested.