2 3. Article 68(1) of the American Convention stipulates that “[t]he States Parties to the Convention undertake to comply with the judgment of the Court in any case to which they are parties.” To this end, the State must ensure implementation at the national level of the Court’s decisions in its judgments.1 4. In view of the final and non-appealable nature of the judgments of the Court, as established in Article 67 of the American Convention, the State must comply with them fully and promptly. 5. The obligation to comply with the decisions in the Court’s judgments corresponds to a basic principle of the law on the international responsibility of the State, supported by international case law, according to which a State must comply with its international treaty obligations in good faith (pacta sunt servanda) and, as this Court has already indicated and as established in Article 27 of the 1969 Vienna Convention on the Law of Treaties, a party may not invoke the provisions of its internal law as justification for its failure to perform a treaty.2 The treaty obligations of the States Parties are binding for all the powers and organs of the State.3 6. The States Parties to the Convention must ensure compliance with its provisions and their inherent effects (effet utile) within their respective domestic legal systems. This principle is applicable not only with regard to the substantive norms of human rights treaties (namely, those which contain provisions concerning the protected rights), but also with regard to procedural norms, such as those referring to compliance with the decisions of the Court. These obligations shall be interpreted and applied so that the protected guarantee is truly practical and effective, bearing in mind the special nature of human rights treaties.4 7. The States Parties to the Convention that have accepted the contentious jurisdiction of the Court are bound to fulfill the obligations established by the Court. This obligation includes the State’s duty to inform the Court of the measures adopted to comply with the aspects ordered by the Court in the said decisions. The timely observance of the State obligation to advise the Court how it is complying with each aspect ordered by the latter is fundamental in order to assess the status of compliance with the judgment as a whole.5 1 Cf. Baena Ricardo et al. v. Panama. Competence. Judgment of November 28, 2003. Series C No. 104, para. 131; Cesti Hurtado v. Peru. Monitoring compliance with judgment. Order of the Inter-American Court of Human Rights of February 4, 2010, third considering paragraph, and El Amparo v. Venezuela. Monitoring compliance with judgment. Order of the Inter-American Court of Human Rights of February 4, 2010, third considering paragraph. 2 Cf. International Responsibility for the Promulgation and Enforcement of Laws in Violation of the Convention (Arts. 1 and 2 of the American Convention on Human Rights). Advisory Opinion OC-14/94 of December 9, 1994. Series A No. 14, para. 35; Cesti Hurtado v. Peru, supra note 1, fifth considering paragraph, and El Amparo v. Venezuela, supra note 1, fifth considering paragraph. 3 Cf. Castillo Petruzzi et al. v. Peru. Monitoring compliance with judgment. Order of the InterAmerican Court of Human Rights of November 17, 1999. Series C No. 59, third considering paragraph; El Amparo v. Venezuela, supra note 1, fifth considering paragraph, and Serrano Cruz Sisters v. El Salvador. Monitoring compliance with judgment. Order of the Inter-American Court of Human Rights of February 3, 2010, fifth considering paragraph. 4 Cf. Ivcher Bronstein v. Peru. Competence. Judgment of September 24, 1999. Series C No. 54, para. 37; Cesti Hurtado v. Peru, supra note 1, sixth considering paragraph, and El Amparo v. Venezuela, supra note 1, sixth considering paragraph. 5 Cf. "Five Pensioners” v. Peru. Monitoring compliance with judgment. Order of the Inter-American Court of Human Rights of November 17, 2004, fifth considering paragraph; García Prieto et al. v. El Salvador. Monitoring compliance with judgment. Order of the Inter-American Court of Human Rights of February 3, 2010, fifth considering paragraph, and Ivcher Bronstein v. Peru. Monitoring compliance with