A party or support enforcement agency seeking to modify, or to modify and enforce, a foreign child-support order not pursuant to the convention may register that order in this state pursuant to Sections 40-6A-601 through 40-6A-608 N.M. Stat. Ann. if the order has not been registered. A petition for modification may be filed at the same time as a request for registration or at another time. The petition shall specify the grounds for modification.