2. Each State Party may adopt more strict or severe measures than those provided for by this Convention for preventing and combating corruption. Article 66. Settlement of disputes l. States Parties shall endeavour to settle disputes concerning the interpretation or application of this Convention through negotiation. 2. Any dispute between two or more States Parties concerning the interpretation or application of this Convention that cannot be settled through negotiation within a reasonable time shall, at the request of one of those States Parties, be submitted to arbitration. If, six months after the date of the request for arbitration, those States Parties are unable to agree on the organization of the arbitration, any one of those States Parties may refer the dispute to the International Court of Justice by request in accordance with the Statute of the Court. 3. Each State Party may, at the time of signature, ratification, acceptance or approval of or accession to this Convention, declare that it does not consider itself bound by paragraph 2 of this article. The other States Parties shall not be bound by paragraph 2 of this article with respect to any State Party that has made such a reservation. 4. Any State Party that has made a reservation in accordance with paragraph 3 of this article may at any time withdraw that reservation by notification to the Secretary-General of the United Nations. Article 67. Signature, ratification, acceptance, approval and accession 1. This Convention shall be open to all States for signature from 9 to 11 December 2003 in Merida, Mexico, and thereafter at United Nations Headquarters in New York until 9 December 2005. 2. This Convention shall also be open for signature by regional economic integration organizations provided that at least one member State of such organization has signed this Convention in accordance with paragraph 1 of this article. 3. This Convention is subject to ratification, acceptance or approval. Instruments of ratification, acceptance or approval shall be deposited with the Secretary-General of the United Nations. A regional economic integration organization may deposit its instrument of ratification, acceptance or approval if at least one of its member States has done likewise. In that instrument of 54