China say they'll look to maintain social order by protecting people against natural disasters, provide aid, and safeguard national security with Honiara.
Australian Foreign Minister Marise Payne said the government was let down over the dealings, raising concerns over the "potential to undermine stability".
"Ultimately, this is a sovereign decision of the government of Solomon Islands and we absolutely recognised that, but … declarations and these engagements on security issues have been dealt with in a Pacific-wide manner," Payne said.
"That is the traditional approach for these issues and it's why some Pacific partners have also raised concerns."
Payne reportedly travelled to the Islands last week, resulting in an unsuccessful bid to stop the deal.
Conversely, the Labor government is accusing their rivals of "the worst failure of Australian foreign policy in the Pacific".
Senator Penny Wong did not mince her words when asked about the failed bid.
"This is the worst failure of Australian foreign policy in the Pacific since the end of World War II," Senator Wong said
"We have China now with a security agreement with a nation of the Pacific, a nation that's just over 1,600 kilometres from Cairns."
"What this means is, on Scott Morrison's watch, our region has become less secure, and the risks Australia faces have become much greater."
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