Which islands in the Solomons chain belong to Papua New Guinea rather than Solomon Islands?

While the Solomon Islands chain is geographically distinct, the nation of Solomon Islands does not encompass the entire archipelago. The islands of Bougainville and Buka, located at the northwestern end of the chain, are politically part of Papua New Guinea, where they form an autonomous region.123

Additionally, several smaller islands in the immediate vicinity of these two, such as Sohano Island, are also included within this autonomous region.24