The multi-stage AUKUS project announced in March is planned to culminate in the late 2030s and early 2040s with British and Australian production and operation of a new submarine class - SSN-AUKUS - and include "cutting edge" US technologies.
"The door's very much open for New Zealand and other partners to engage as they see appropriate going forward," Blinken told a news conference in Wellington on Thursday.
"We've long worked together on the most important national security issues. And so as we further develop AUKUS, as I said, the door is open to engagement."
Blinken's remarks contrasted slightly with those made less than a day earlier by Australian Prime Minister Anthony Albanese who said there were "no plans" to extend the Aukus agreement beyond its current three-country parameters.
"We already have an important relationship in defence and one if the things pillar II is about is essentially use of tech … there are no plans at this point in time to extend beyond the Aukus pillar I and pillar II arrangements," he said.
"That doesn't mean that there won't be cooperation across a range of areas as well including access to technology, including complementarity including interoperability."
Blinken met with New Zealand Prime Minister Chris Hipkins and Foreign Minister Nanaia Mahuta, who said NZ is open to discussions on a second phase of AUKUS focusing on military technology.
However, Mahuta reiterated that NZ was "not prepared to compromise or change our nuclear-free position" and that it continued to support a nuclear-free Pacific.
She said her discussions with Blinken were warm and personal and they had covered the international rules-based order, the increasingly contested global environment including in the Pacific, and highlighted the two countries' commitment to democracy and human rights.
New Zealand and the US describe themselves as close strategic partners, although their alliance was suspended in the 1980s when NZ barred visits from US nuclear-powered or armed warships.
Their relationship has become increasingly close in the past couple of years due to mutual concerns about China's presence in the Pacific, particularly Beijing's growing defence and policing ties with the Solomon Islands and its potential destabilising effect in the region.
Mahuta said while New Zealand respected the Solomon Islands' independence, it also supported regional agreements that ask Pacific countries to come together when making decisions that could impact the region.
Blinken will travel to Australia later on Thursday where the largest Australia-US military exercise is due to begin.
with AAP
