(18)The competent authorities of the United States intend to further evaluate the auditor oversight systems in the Member States before deciding to fully rely on the oversight performed by their competent authorities. Therefore, the mechanism of cooperation between the competent authorities of the Member States and the competent authorities of the United States should be reviewed to assess the progress made towards reaching mutual reliance on each other's oversight systems. For that reason, this Decision should be applicable for a limited period of time.