A/HRC/10/48 page 9 constitutional level, similar to other human rights treaties. Moreover, in several States such as Croatia, Mali, Mexico and Niger, international human rights treaties to which the State is a party are regarded as standing above national laws. 26. Human rights treaty bodies have often addressed the issue of the place of international human rights treaties in the domestic legal hierarchy, demanding clarity as to the level of the treaty. Appreciation has been consistently expressed for States that have recognized human rights treaties as holding constitutional status. The Human Rights Committee explicitly noted that prevalence of international human rights treaties even above constitutional norms “flows directly from the principle contained in article 27 of the Vienna Convention on the Law of Treaties, according to which a State Party ‘may not invoke the provisions of its internal law as justification for its failure to perform a treaty’”. The Committee noted that this principle “operates so as to prevent States parties from invoking provisions of the constitutional law or other aspects of domestic law to justify a failure to perform or give effect to obligations under the treaty”.23 27. Reservations lodged by States that do not recognize the predominance of the Convention in case of a conflict between the Convention and constitutional or national laws might present challenges from the perspective of compatibility with article 27 of the Vienna Convention. C. General legal obligations 28. Article 4 of the Convention on the Rights of Persons with Disabilities defines the scope of the general legal obligations undertaken by States parties. It requires States “to ensure and promote the full realization of all human rights and fundamental freedoms for all persons with disabilities without discrimination of any kind on the basis of disability” and provides the overarching framework within which the rights specified in the Convention are to be promoted and protected. States are required to “refrain from engaging in any act or practice that is inconsistent” with the Convention and to “adopt all appropriate legislative, administrative and other measures for the implementation of the rights recognized in the … Convention”. Treaty bodies monitoring other human rights treaties have indicated that appropriate measures for implementation of human rights obligations may include legislative, judicial, administrative, educational, financial and social measures.24 29. By requiring States to give effect to their obligations “by all appropriate measures”,25 the Convention on the Rights of Persons with Disabilities adopts a broad and flexible approach to implementation that allows for the legal particularities of each State to be taken into account, including in particular the status of the treaty in the domestic legal order, as well as other 23 Human Rights Committee, general comment No. 31, para. 4. 24 Ibid. or CESCR, general comment No. 3 (1990) on the nature of States parties’ obligations (art. 2, para. 1 of the Covenant). 25 CRPD, art. 4, para. 1 (a).