Australia's Foreign Minister Penny Wong defended multiculturalism as "the only Australia that has ever existed" in a speech on Friday, pushing back against the ascendant far-right One Nation party.
Malaysian-born Wong -- the first Asian-Australian to become a federal minister -- warned against "external and internal forces" seeking to divide the country in her address to the Lowy Institute in Sydney, highlighting the success of refugees in business and sport.
Half of Australians were born overseas or have a parent who was, census data shows.
"Multicultural Australia is the only Australia that has ever existed," Wong said.
The "melancholic fantasy of a monoculture" would cause damage to Australia's international security and trade by cutting off connection to the world, she added.
Pauline Hanson's One Nation has surged this year to become the country's most popular party and could gain a kingmaker role at the next election in 2028, according to opinion polls.
Hanson -- long compared to US President Donald Trump or France's Marine Le Pen -- has called for a "monoculture", and said One Nation wants Australia to re-evaluate its ties with international organisations and cut aid.
The senator drew outrage this year for referencing the "White Australia" policy -- which restricted non-white immigration in the 1970s.
"Those who seek to divide us for clicks and votes should know that they make us weaker at home and more vulnerable in the world," Wong said.
Australia and other middle powers are facing difficulty holding their "strategic space" in the world, as "military power, economic coercion, and control of the materials and technologies the world depends on, are used too often to constrain choices", she said.
Australia needed to diversify its global relationships, as well as strengthen ties with security partners the United States and Britain, she added.
The deployment of North Korean troops to fight with Russia in Ukraine saw "two regional conflicts being connected in a really open way and was pretty deeply problematic", she said, citing it as an example of strategic balance being challenged.
Australia's centre-left Labor government is preparing to announce an immigration policy change, and has said there are "legitimate concerns" about the economy and housing driving the rise in support for the far-right.
"Modern Australia is multicultural," Prime Minister Anthony Albanese said on Friday, referencing his own Italian family name.
Immigration levels are falling from a peak, and would be reduced "without vilifying people, without trying to divide the community, but bringing people together in the national interest", he told reporters.