And there are reasons of State which make this visit essential.
国家的大计使这次访问成为必然。
是，大臣（Yes, Minister）第一季
Minister, we do not hold Head of Government visits for party political reasons, but for reasons of State.
大臣阁下，我们不能因为党派政治而举行政府首脑访问，要站在国家立场上考量。
纳尼亚传奇（同步字幕版）The CHRONICLES of NARNIA C.S LEWIS
How should you understand reasons of State?
你应该如何理解状态的原因？
英语百科
National interest
The national interest, often referred to by the French expression raison d'État ("reason of State"), is a country's goals and ambitions whether economic, military, or cultural. The concept is an important one in international relations where pursuit of the national interest is the foundation of the realist school.