The Australian government listed Hezbollah as a "terrorist organisation" on Wednesday, extending an existing ban on armed units to the entire organisation which holds considerable power in Lebanon.
Home Affairs Minister Karen Andrews said that the Tehran-backed Shiite group "continues to threaten terrorist attacks and provide support to terrorist organisations" and poses a "real" and "credible" threat to Australia.
Hezbollah defies easy definition, acting as part political party, part militant organisation, and part provider of basic services to Lebanon's Shiite community.
It is the only group in Lebanon to have refused to disarm since the civil war ended in 1990.
The movement, which plays a pivotal role in Lebanese politics, has been accused of fuelling Syria's civil war by sending thousands of fighters across the border to prop up President Bashar al-Assad's regime.
In 2006, it fought a short yet devastating war against Israel.
Critics have accused the movement of killing former prime minister Rafik Hariri in 2005, and more recently of blocking investigations into the cataclysmic 2020 Beirut port explosion.
Some countries have sought to distinguish between Hezbollah's political and militant factions, fearing a blanket ban could further destabilise Lebanon and hamper contacts with authorities.
Australia had such a policy since 2003 when it banned Hezbollah's so-called External Security Organisation – a part of the movement's military wing that is chiefly focused on shadowy overseas operations.
From now, membership of the entire organisation or providing funding for it will now be proscribed in Australia, which has a large Lebanese community.
Israeli Prime Minister Naftali Bennett thanked his "friend" and Australian counterpart Scott Morrison for the move.
"Hezbollah is an Iranian-backed terror organization in Lebanon responsible for countless attacks in Israel & around the world," he tweeted.
No reason was given for the timing of Canberra's decision, which comes as Lebanon reels from spiralling political and economic crises.
The move may play well domestically for Australia's conservative government, ahead of its own elections expected next year.
Australia's government also announced Wednesday that it would be listing far-right group "The Base" as a terror group.
"They are a violent, racist neo-Nazi group known by security agencies to be planning and preparing terrorist attacks," Andrews went on.