Prime Minister Tony Abbott declared Australians and Canadians to be "family" facing a common danger as Federal Parliament stepped up security on Thursday in the wake of the attack in Ottawa.
Underscoring the similarities between the two countries, including their shared problem of citizens travelling to the Middle East to fight alongside extremists, Mr Abbott said that aside from New Zealand, "no country on Earth is more akin to Australia than Canada".
"We are both multicultural federations with British institutions," he said. "They speak our language and they share our heritage and our danger.
"More than 100 Canadians are believed to be fighting with the ISIL [Islamic State] death cult and other terrorist groups in the Middle East, and more have been infected with godless fanaticism. Today more than ever, Australians and Canadians are family."
Parliament House in Canberra, which has undergone a significant security boost in recent weeks, was given further increased security on Thursday morning after the fatal assault in Canada's capital.
Speaker Bronwyn Bishop told MPs on Thursday morning: "You will notice some increase in the security arrangements this morning. You will also note we have a significant armed presence guarding the building, which has recently been boosted with the addition of long-armed weapons."
Opposition Leader Bill Shorten said Australia stood with Canada in its fight against terrorism.
"We will never surrender to hatred, violence or extremism," he said.
Canada's Conservative Prime Minister Stephen Harper – whom Mr Abbott described on Thursday as "a friend and almost a brother" – has, like Mr Abbott, authorised fighter jets and special forces advisers to help Iraq in the fight against the Islamic State.
Both countries have featured prominently in the Islamic State's online diatribes, in which the group urges its global followers to kill.
Foreign Affairs Minister Julie Bishop said she had sent a text message to her Canadian counterpart, John Baird, at 4am. He told her he was about 15 metres away when the gunman was shot dead in the parliament building's Hall of Honour, where Mr Abbott recently met Mr Harper.
"The body was lying just outside the door where [Mr Baird] was," Ms Bishop said. "He is safe but clearly very shaken by what is a shocking incident."
Canadian national security expert Wesley Wark told Fairfax Media that parliamentary security in Ottawa included armed police outside the building and armed guards within it – similar to Canberra's arrangements since the recent upgrade.
He said that, like Australia, Canada faced a significant threat of low-tech attacks by extremists who might never have travelled or gained serious training, but are being influenced by events in the Middle East.
"We've been worried about the foreign fighter phenomenon, as I know you have in Australia. Maybe we've been over-worried about that and lost sight a little bit of the home-grown terrorism dimension," Associate Professor Wark said.
Both countries have foiled major plots in the post-September 11 period, Canada's most prominent being the "Toronto 18", in which conspirators planned to storm parliament and behead the prime minister and also attack the national broadcaster and state intelligence buildings.
