A surge of navy ships to Australia's north has sparked accusations of Labor going soft on borders after granting asylum seekers more visa rights.
The Defence department told a Senate estimates hearing it had provided surge support to Operation Sovereign Borders in the past few weeks, providing surveillance aircraft and ships to Australia's north.
The extra defence assets followed a request from the national security agency.
"The defence force generally surges as is required to support Operation Sovereign Borders ... that is available to the government to employ the ADF in that nature, and we are currently providing surge support," Vice Admiral David Johnston said.
"It is of the nature of additional aircraft surveillance and additional ships that are patrolling in our northern waters."
The government this week announced 19,000 temporary protection or safe haven enterprise visa holders could apply for permanent residence from late March.
Only asylum seekers who entered Australia before Operation Sovereign Borders began in 2013 are eligible to apply.
Opposition home affairs spokeswoman Karen Andrews said the need to provide extra ships up north was "clearly" due to the government's decision regarding temporary protection.
"The Labor government has systematically gone about pulling apart the key pieces of Operation Sovereign Borders, and in so doing has effectively opened our borders to the people smugglers," she told reporters.
"Many of us would remember the impact of Labor's failed border policies, boat arrivals, the people dying ... the visions of people being plucked out of the water."
Ms Andrews said Home Affairs Minister Clare O'Neil was "missing in action" and the government was warned of potential impacts of granting permanent residency.
"The government was warned about the impacts of changes to the policy but they have gone ahead and they have made changes, which have left us vulnerable here in Australia."
