The action was taken ahead of a bond sale for a controversial 15-year expansion program that is currently estimated to cost $8.2 billion up from $5 billion.
Border cities like San Diego have obvious concerns about the impact of a trade war, but the ripples would extend into the South and Midwest, analysts say.
Muni mutual funds saw outflows after 23 weeks of inflows as LSEG Lipper reported investors pulled $316.2 million for the week ending Dec. 11 after $1.15 billion of inflows the previous week.
U.S. District Judge Laura Taylor Swain ordered Puerto Rico Electric Power Authority parties to return to mediation despite the mediators' determination further talks would be fruitless.