When Federal funds are available for payment of the items specified in this Section, the displacing agency may match such Federal funds to the extent provided by Federal law and may make such payments in the instances and on the conditions set forth by Federal law and regulations.
When such Federal funds are available and as soon as practicable after the date of payment of the purchase price or the date of deposit in court of funds to satisfy the award of compensation in a condemnation proceeding to acquire real property, whichever is the earlier, the State agency shall reimburse the owner, to the extent the head of such agency deems fair and reasonable, for expenses he necessarily incurred for--
310 ILCS 40/2a