Solomon Islands Prime Minister Manasseh Sogavare said Wednesday his government signed a controversial security pact with China "with our eyes open" but refused to say when it may be published.

The deal, announced by Beijing on Tuesday, has been sharply criticised by the island state's allies the United States and Australia, which fear it could lead to China gaining a military foothold in the South Pacific.

Sogavare told parliament it was an "honour and privilege" to announce that the deal had been signed by officials in Honiara and Beijing "a few days ago".

But he declined to tell the opposition leader when the signed version of the pact would be made public. A bilateral security deal with Australia was published several years ago.

A draft version of the China deal sent a shockwave across the region when it was leaked last month, particularly measures that would allow Chinese naval deployments to the Solomon Islands.

The broad wording of the draft deal prompted a flurry of diplomatic overtures from the United States and Australia to prevent it from being signed but they were ultimately unsuccessful.

Map and graphic factfile on the Solomon Islands.
Map and graphic factfile on the Solomon Islands. AFP / Laurence CHU

Sogavare said the China deal "complements" his country's existing treaty with Australia.

He argued that if the Solomon Islands had continued under the status quo, it would not be able to cover "critical security gaps".

"Let me assure the people that we entered into an arrangement with China with our eyes open, guided by our national interests," he said.

Sogavare asked all of his nation's "neighbours, friends and partners to respect the sovereign interests of the Solomon Islands".

Australian Foreign Minister Marise Payne criticised the Solomon Islands Wednesday for "a lack of transparency" and a failure to consult with other Pacific nations about the deal.

She defended not travelling to the Solomons herself to advocate against the pact as Australia's top foreign policy figure -- instead, the country's Pacific Minister Zed Seselja visited last week and asked Sogavare not to sign it.

The United States's top Asia official Kurt Campbell will arrive in the Solomon Islands later this week along with Daniel Kritenbrink, the assistant secretary of state for East Asian and Pacific affairs.