(10)The competent authorities of the United States intend to further evaluate the systems of public oversight, quality assurance and investigations and penalties in the Member States before deciding to fully rely on the oversight performed by their competent authorities. Therefore, considering that the derogation provided for in Article 46 of Directive 2006/43/EC is based on the principle of reciprocity, 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. That review should also take account of the fact whether the Member States encountered difficulties in obtaining recognition of equivalence in respect of their public oversight, quality assurance, investigation and penalty systems for auditors and audit firms by the competent authorities of the United States. For that reason, this Decision should be applicable for a limited period of time.