system of government; government structure
Refers to the overall framework of governance, including institutions, laws, and administrative bodies.
This country's system of government is complex, and the separation of powers is not clear.
Under the new constitution, the government structure changed significantly.
政治体制 refers more to the political regime or system (e.g., democracy, dictatorship), while 統治機構 emphasizes the institutional and structural aspects of governance.
Compound of 統治 (governance, rule) and 機構 (mechanism, structure). The exact historical derivation is uncertain, but the term is used in modern political and legal contexts.