(Buzz, expressions of hesitance) "The United Nations, together with a European nation", repeated USA's leader, "discovered Papuan area for exotic fish" (21)
This is a cryptic clue with the solution:
UH UM[expressions of hesitance]
UN[the United Nations]
UK[a European Nation]
UN UK[[last two parts] repeated]
APUA[dis-covered "papuan" (i.e. missing its "cover", or outer letters)]
together forming HUMUHUMUNUKUNUKUAPUA'A, the state fish of Hawai'i (also known as the reef triggerfish).