Phnom Penh and Canberra signed an agreement Friday for the resettlement of Australia-bound refugees in Cambodia, a deal the U.N. criticized as a "worrying departure from international norms".

Under its hardline immigration policy Australia already sends asylum-seekers arriving by boat to camps on Manus Island in Papua New Guinea and the remote Pacific state of Nauru for processing and resettlement.

A terror suspect shot dead by Australian police after stabbing two officers in a frenzied knife attack may not have been acting alone, officials said Thursday, escalating concerns about the threat posed by radicalized youth.

Abdul Numan Haider, 18, was killed on Tuesday evening on the outskirts of Melbourne, a day after the Islamic State group called for Muslims to indiscriminately kill Australians.

Australia confirmed Thursday it will sign an asylum-seeker resettlement deal with Cambodia in a move slammed by human rights groups as violating the country's international obligations.

Immigration Minister Scott Morrison will be in Phnom Penh on Friday to seal the deal, which could see some asylum-seekers currently held in offshore detention camps by Australia transferred to the Southeast Asian nation.

Police have shot dead a "known terror suspect" who stabbed two officers, a day after the Islamic State group called for Muslims to indiscriminately kill Australians, officials said Wednesday.

The 18-year-old, reportedly associated with the Islamic group Al-Furqan, was killed on Tuesday evening, having arrived at a police station on the outskirts of Melbourne to attend a "routine" interview.

Foreign Minister Julie Bishop on Tuesday said Canberra was treating as genuine a call by the Islamic State group for Muslims to indiscriminately kill Australians, issued after anti-terrorism raids foiled an alleged abduction plot.

The militants on Monday released a statement urging the deaths of citizens of all countries taking part in the U.S.-led coalition against the jihadists. Australia was mentioned, along with the United States, Canada and France. 

Australian fighter jets are being deployed to the Middle East to join the U.S.-led campaign of air strikes on jihadist targets in northern Iraq, Defense Minister David Johnston said Monday.

"We will provide a number of military platforms, up to eight Super Hornet aircraft to participate in a U.S.-led coalition in delivering air strikes," he told reporters in Baghdad after meeting Iraqi Prime Minister Haider al-Abadi.

Prime Minister Tony Abbott on Monday warned Australians fighting with extremist groups in the Middle East they face lengthy jail terms if they return home.

"My unambiguous message to all Australians who fight with terrorist groups is that you will be arrested, prosecuted and jailed for a very long time," Abbott told parliament in a statement on national security.

New Zealand Prime Minister John Key said Monday he would press ahead with plans to hold a referendum to change the national flag following his election triumph.

The center-right leader said he wanted the ballot next year on whether to ditch the current flag, which features the Union Jack of former colonial power Britain in one corner.

Australia's government will next week introduce tough new legislation in parliament to tackle a growing threat of terrorism, reports said Saturday, in the aftermath of the biggest crackdown in the country's history.

Prime Minister Tony Abbott will seek sweeping counter-terrorism powers when the proposals go before the house on Wednesday, NewsCorp Australia reported.

Vladimir Putin is set to attend the G20 leaders' summit in November despite alarm over Russia's actions in Ukraine with host Australia Saturday saying it was the "emphatic" wish of member nations.

There had been question marks over whether Moscow should be invited to the high-powered forum in Brisbane with the brutal five-month conflict that has killed around 3,000 people still unresolved.