Sovereign Debt Management

Introduction International financial markets assign the status of "sovereign debt" to the public debt issued by governments. This status reflects the highest quality debt issuers in the market, and most with the strongest credit rating. Domestic public debt has a very significant and unique role as a high credit quality investment with normally a high degree of liquidity, best illustrated by the US Treasury market.

这里出现得几处“sovereign”该怎么翻译呀？