Oman

The political principles of the state consist of the following:
…
– Strengthening ties of cooperation and affirming bonds of friendship with all states and nations on the bases of mutual respect, common interests, non-interference in internal affairs, and the adherence to international and regional charters and treaties, as well as generally recognised principles of international law, in a manner conducive to the advancement of peace and security among states and nations.
... (Art. 13)

The application of this statute shall not prejudice treaties and agreements that the Sultanate has entered into with states and international authorities and organisations. (Art. 89)

International treaties and agreements do not have the power of law except after their ratification, … (Art. 93)

It is not permitted for any entity in the state to issue regulations, decisions, or instructions that contradict the provisions of the laws and royal decrees in force, or international treaties and agreements that are considered part of the law of the land. (Art. 97)