A new security deal between Solomon Islands and China is causing consternation among neighbouring Pacific islands, including Australia and New Zealand.

The deal is expected to allow Chinese navy ships and defence forces to be based in the Solomons to protect billions of dollars in Chinese infrastructure investment in the developing country.

It will be signed after days of lobbying from Australia and New Zealand to reconsider and is seen as a failure of decades of engagement with the Pacific region.

The Solomon Islands is a key strategic point in the Pacific, providing access to shipping lanes from Australia and New Zealand up through Asia, and the presence of Chinese navy ships could potentially cut off supply lines in the event of conflict.

Today on Please Explain, North Asia correspondent for The Age and the Sydney Morning Herald Eryk Bagshaw joins Nathanael Cooper to discuss what the deal means for Australia.