Australian Prime Minister Anthony Albanese was sworn in for a second term on Tuesday, alongside his ministers, after a landslide win at a national election he said had returned the largest centre-left Labor government since federation in 1901.

Albanese's Labor Party rode a voter backlash against global instability caused by US President Donald Trump's policies to a come-from-behind victory on May 3.

The opposition conservative Liberal Party, whose leader Peter Dutton lost his seat at the election, selected Sussan Ley as its new leader on Tuesday.

Ley became the first woman leader of the federal Liberal Party, which lost city seats in Sydney and Melbourne to women who ran as independent candidates with policies supporting climate change and gender equality in the last two elections.

The Australian Electoral Commission is yet to finalise vote counting in several seats, although Labor said it is ahead in at least 94 seats out of the 150-seat House of Representatives.

It was the largest Labor caucus since Australia was formed by the federation of six former British colonies in 1901, Albanese said.

Albanese and his ministers were sworn in at a ceremony at Government House in Canberra, conducted by Governor-General Sam Mostyn.

The key roles of treasurer, foreign affairs, defence and trade are unchanged. In new roles, Michelle Rowland was sworn in as attorney-general, Murray Watt as environment minister, and Tanya Plibersek as social services minister.

Albanese will travel to Indonesia on Wednesday, and will attend the inauguration mass of Pope Leo XIV on Sunday in Rome, where he said he would also hold meetings with other leaders including European Union president Ursula von der Leyen to discuss trade.

Ley said her appointment "sent a signal" to Australian women, although her agenda would be "much more than that", flagging the need for new policies on economic and tax reform.

"We did let women down, there is no doubt about that, and it is true that the number of women supporting us is declining and I want to rule a line under that," she said in Canberra, reflecting on the conservative party's loss.

The Liberal Party needs to "meet modern Australia where they are", she said.

"Government is always formed in the sensible centre," she added.

A former aerial stock mustering pilot who raised three children on a farm before graduating from university, Ley entered parliament in 2001. (Reuters)