The United States Defence Department could help pay for a new cable linking New Zealand, Australia, the United States and several Pacific Islands, an Auckland source says.

He said the department had an interest in spending about US$100 million (NZ$120m) to directly or indirectly acquire a pair of optical fibres between the US, Australia and American Samoa to link its defence bases.

The interest has not been confirmed by the US Government or the Hawaiki company, which have been approached for comment.

The US said in 2011 that it would build a permanent base for thousands of US Marines in Darwin.

The Australian Government said in June that the number of Marines at the base would rise from between 200 and 250 to 1150 next year. By 2016, it would support a 2500-strong Marine Air Ground Task Force.

If interest in a fibre link translated into a contract, that could be a big boost for Hawaiki Cable, a New Zealand-based venture headed by former Alcatel-Lucent chief executive Remi Galasso, the source said.

Hawaiki is building a business case for a 14,000-kilometre cable network that it hopes to lay in 2015 at a cost of US$350m (NZ$420m).

The network would connect the US, Australia and New Zealand, with spurs to several Pacific Islands, including American Samoa.

The company this week signed a letter of intent with Australia's fourth-largest internet provider, TPG Telecom, which has expressed interest in buying tens of millions of dollars worth of capacity on its Sydney-US and Sydney-Whangarei links.

Hawaiki said last month that it had signed a memorandum of understanding with regional development agency Northland Inc to land the proposed cable in the Whangarei area.

There is currently one fibre-optic cable with two fibre-pairs connecting American Samoa to Hawaii – the Ash cable, which was put into service in 2009.