The US president has hosted Prime Minister Anthony Albanese at his personal home, in what could be the last official one-on-one meeting between the leaders.

Joe Biden welcomed Mr Albanese to his property in Wilmington, Delaware, ahead of an annual gathering of the Quad — a grouping that also includes India and Japan.

"My understanding is it was the first time that a foreign leader has met him at his home," the prime minister said afterwards in the nearby city of Philadelphia.

"And so I feel that it was a great honour for that."

The president has invited Quad leaders to visit his hometown four months before his term in the White House comes to an end.

Asked about the concerns around Mr Biden's age and capacity to do the job that saw him withdraw from this year's election, Mr Albanese argued the president was "fit and totally on top of his brief".

"I regard him as a friend and, importantly, someone who I can learn from," he said.

The pair swapped gifts, as is traditional on such visits, with Mr Albanese giving the president an official Royal Australian Air Force flight jacket with a "Joe Biden" name patch.

The prime minister received a framed artwork depicting Delaware landmarks, made with wood sourced from the state.

"Today, I met with my friend, Prime Minister Albanese, to strengthen our innovation alliance so we can tackle shared challenges together," Mr Biden said on X.

"When America and Australia stand as one, we forge a future of greater opportunity and security for our countries and the Indo-Pacific."

Safeguarding the Quad partnership amid political uncertainty

The Quad partnership first arose in response to the 2004 Boxing Day tsunami, before being revived by Donald Trump's administration.

It was elevated to the leadership level under Mr Biden, in a bid to help counter China's expanding influence in the Indo-Pacific.

White House National Security Council spokesman John Kirby said earlier this week that China would be high on the agenda, arguing it would be "irresponsible" for the Quad not to address challenges "caused by aggressive PRC [People's Republic of China] military action, for instance, unfair trade practices [and] tensions over the Taiwan Strait".

The Quad meeting is being held at Mr Biden's former high school, Archmere Academy, and will be followed by a private dinner on the grounds.

The US has flagged announcements around the president's "Cancer Moonshot" initiative, which aims to prevent millions of cancer deaths, as well as further cooperation on work to combat illegal fishing in the Indo-Pacific region.

Mr Biden's imminent departure from the White House is not the only upcoming change to the Quad, with Japanese Prime Minister Fumio Kishida stepping down later this month.

However, the White House this week sought to downplay concerns about uncertainty over the grouping's future.

"You'll see signs that the Quad is not just the initiative of any one administration or any one country, but an initiative that is designed to endure for the long term," National Security Council advisor Mira Rapp-Hooper said.

A bipartisan group of US representatives and senators also announced a new "Quad caucus" in Congress ahead of the meeting.

"As the Indo-Pacific becomes increasingly important to global security and economic prosperity, it is essential that the United States continues to strengthen relationships with our Quad partners," Democratic representative Ami Bera said in a joint statement.

"Partnerships like the Quad are our greatest strength in protecting a prosperous, free and open Indo-Pacific against coercion and malign aggression," Republican senator Pete Ricketts added.

Prime minister visits US against backdrop of turbulent election campaign

Former US president and current candidate Donald Trump says he is expecting to meet Indian Prime Minister Narendra Modi while he is visiting the country for the Quad gathering.

However, Mr Albanese is not expected to use his trip to sit down with either Mr Trump or the Democratic candidate, Vice-President Kamala Harris.

The prime minister would not be drawn on the upcoming US election, other than to reflect on the political violence that has marred a campaign that has included two apparent attempts on Trump's life.

"There's no place for violence in democratic processes, whether it be the extreme examples of assassination attempts, obviously, but other forms of violence as well," Mr Albanese said.

"People should be able, in a democracy, to express their views and express them peacefully and respectfully to each other."

The prime minister is scheduled to leave the US once the Quad events wrap up.