Malaysia, Indonesia and Thailand triggered outrage after turning back starving and helpless migrants from Bangladesh and Myanmar's oppressed Muslim Rohingya minority with little food and nowhere to go, and have come under increasing pressure to rescue them.
The Australian leader, whose government introduced tough measures to stop asylum-seeker boats, said he was "in no way critical of regional countries for the efforts that they make to stop the boats".
"I don't apologise in any way for the action that Australia has taken to preserve safety at sea by turning boats around where necessary.
"And if other countries choose to do that, frankly, that is almost certainly absolutely necessary if the scourge of people smuggling is to be beaten."
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After coming into power in September 2013, Australia's conservative government introduced a military-led operation to turn back boats carrying asylum-seekers before they reach the island continent.
The government has credited the controversial policy for the nation going nearly 18 months with virtually no asylum-seeker boat arrivals and no reported deaths at sea, although human rights advocates have slammed it for violating Australia's international obligations.
Before the policy was introduced, boats were arriving almost daily with hundreds of people drowning en route.
"That's why the heart of this is stopping the boats."
Abbott's comments came as Malaysian Prime Minister Najib Razak said he would seek help from Myanmar to address the influx of migrants, Southeast Asia's biggest since the end of the Vietnam War.
But Myanmar's government -- which denies the Rohingya citizenship -- has already rejected a Thai call for a regional summit on the issue on May 29, saying it was not their problem.