SYDNEY (AFP) - Prime Minister Tony Abbott said on Thursday he was "very satisfied" as Australia marked six months since the last asylum-seeker boat arrival, but warned it was not yet "mission accomplished".
Abbott's conservative government came into power in September vowing to stop the flood of asylum-seekers arriving on rickety boats from its South-east Asian neighbours, with hundreds of people dying en route.
Under its offshore detention policy, asylum-seeker vessels are now controversially turned back to Indonesia and would-be refugees sent to Papua New Guinea and Nauru in the Pacific for processing and resettlement.
"I'm not declaring victory. There is no hint of mission accomplished about today," Mr Abbott said in praising Immigration Minister Scott Morrison for "a really outstanding job".
"But nevertheless this is a very satisfactory milestone that we've had six months since the last successful people-smuggling venture to Australia." Over the same six-month period in 2012/13 under the previous Labor government, 190 boats with 12,773 people on board illegally arrived in Australia, figures show.
Mr Abbott would not reveal how many boats had been sent back during the military-led Operation Sovereign Borders. "The last thing I want to do is to compromise the effectiveness of our operations by giving out information that will just be used by those... who would put people's lives at risk by running people-smuggling ventures," he said.
"A full account of all of this will one day be given, but not yet." The turn-back operations have angered Indonesia, with tensions between the two countries growing after the Australian navy admitted entering the nation's territorial waters.
The United Nations and refugee advocates have repeatedly slammed the government's hardline policy with critics condemning the conditions at offshore detention centres as being too harsh.
A riot at the PNG facility on Manus Island in February left an Iranian asylum-seeker dead and 69 people injured as frustrations over their fate and conditions boiled over.
Mr Abbott's comments came a day after Australia's highest court dismissed a challenge to the policy of sending asylum-seekers to PNG, ruling that detention at the immigration camp was legal.
The case was brought by an Iranian who arrived at Australia's Indian Ocean territory of Christmas Island by boat in July 2013 and was transferred to Manus Island.