Classified US diplomatic cables from 2006 show that the US enjoyed close contacts with the Solomon Islands foreign minister at the time, Laurie Chan.
The Solomon Star says according to cables published by WikiLeaks, the minister assured the US ambassador that he would back Guatemala's bid to be on the UN Security Council.
This comes after revelations that the Australian high commissioner, Patrick Cole, discussed his views on the possible choice of prime minister with Mr Chan.
Mr Cole reportedly described as depressing that the choice in 2006 was between Snyder Rini, Manasseh Sogavare and Job Dudley Tausinga.
Mr Cole allegedly considered electing any of them as not good for the future of RAMSI because they were unlikely to be an effective voice to represent Australia's interests in Cabinet.
Parliament elected Mr Rini but after a riot he resigned and parliament chose Mr Sogavare.
The Solomon Star also says Canberra ran an intelligence unit in Solomon Islands, known as the Australian Intelligence Community.
The intelligence unit reportedly kept the attorney-general at the time, Julian Moti, under surveillance.
Mr Moti, who is an Australian citizen, was extradited in 2007 to face sex charges but has not been convicted, with Mr Moti now challenging the legality of his deportation to Queensland.