"Under the Morrison government, the reelected Morrison government, our policy on boats have not changed. There will be no softening of our border protection measures and people will be returned to their country of origin as we have demonstrated."
Earlier on Thursday, new Labor leader Anthony Albanese hit back at claims that Labor was responsible for the most recent people smuggling operation, pointing out the government has been in charge of borders for the past six years.
"There have been 10 boats come from Sri Lanka on this government's watch, 10, not one," he said.
"I think it is the respectful thing for me to do to have a discussion with the Prime Minister this afternoon."
But Mr Dutton called on Mr Albanese to distance himself from former leader Bill-Shorten's border policy, in order to stem further people smuggling attempts.
He also urged the Labor leader to abandon his support for the controversial Medevac law, which streamlined the process for offshore refugees and asylum seekers to get urgent medical care.
"That [the Medevac law] is a pull factor for people on boats as well," he said.
"People smugglers have the Labor party worked out."
Earlier on Thursday, an Australian Border Force spokesperson confirmed the vessel, which was carrying at least one baby among the 20 asylum seekers, was spotted last week in the Indian Ocean, heading towards Australia's north-west coast.
During the media conference, Mr Dutton also confirmed that the boat did not reach Christmas Island - the location of a recently reopened offshore detention centre - and that none of the asylum seekers were detained at the centre, as was earlier reported.
It was earlier reported the vessel reached the island and the group were briefly detained there.
So far 186 asylum seekers from 10 people smuggling boats have been sent back to Sri Lanka since the Coalition won government in 2013, according to the Australian Border Force.
The latest boat left Sri Lanka in the first week of May, shortly after the deadly Easter terror attacks on hotels and churches that left more than 250 people dead.
During the election campaign, the prime minister and then-Opposition Leader Bill Shorten pledged ongoing support for the boat turnbacks policy.
"There's no doubt that people smugglers have been telling innocent men, women and children that hop on a boat that the circumstances will change if there is a Labor government," Mr Dutton said.
"We don't want kids back in detention and we don't want people drowning at sea."