US President Joe Biden on Tuesday called Australia the most reliable ally of the United States, adding that the partnership will advance on the vision for a free and open Indo-Pacific.

"The United States has no closer or more reliable ally than Australia. Our nations have stood together for a long, long time. And you can - we can rely on one another, and that's really a reassuring thing," Biden said before a bilateral meeting, according to a White House release.

Earlier, Joe Biden met Australian Prime Minister Scott Morrison during the 76th Session of the UN General Assembly in New York City.

"We are grateful that our partnership has accomplished what we've accomplished together over 70 years," added the statement.

"The United States and Australia are working in lockstep on the challenges that I laid out today in my speech to the United Nations: ending Covid, addressing the climate crisis, defending democracy, shaping the rules of the road for the 21st century. Because I meant what I said: We are at an inflection point; things are changing. We either grasp the change and deal with it, or we're going to be left behind - all of us," Biden said.

Biden also said that they have big agenda to discuss, starting with the US-Australia partnership for a free and open Indo-Pacific.

"This conversation that we are going to continue with Japan, India - and India, on Friday, and -- in the first in-person Quad leaders meeting is a historic event. And we're - I think we are all looking forward to it," added the statement.

Biden will also host the first in-person Leaders' Summit of the Quadrilateral Framework in Washington on September 24.

Responding to Biden, Scott Morrison thanked him for the warm welcome that marks the 70th anniversary of Australia, New Zealand, and US (ANZUS) alliance.

"I think it's very important we are meeting here in New York. This month, we mark the 70th anniversary of the ANZUS alliance. There have been 14 Australian Prime Ministers since Sir Robert Menzies and 14 US Presidents that have stewarded this great partnership," said Morrison.

Referring to September 11 terror attack, Morrison said that the ANZUS alliance was invoked when the towers came down in New York.

"The one time the ANZUS alliance was invoked was when the towers came down here in New York and were attacked. And that invoked the ANZUS alliance for the first and only time. And so, to both mark that event and remember all of those who were lost on that day, we reflect on, frankly, more than a 100 years of our partnership where we have stood together through the most difficult of times and the most prosperous of times," Morrison added.

He also said that Australia-US shares a partnership that favours freedom.

"And the United States and Australia have always shared a partnership that is about a world order that favours freedom, and that's why we've always stood together," he said.

He also talked about the European Union (EU) and the Association of Southeast Asian Nations (ASEAN) and said that the US-Australia partnership shares like-minded interests.

"But it's not just about our partnership, because our partnership reaches out to so many others, whether it be our friends in the ASEAN nations or in Europe or elsewhere, where we share so many like-minded interests. And so, the issues we discuss in our partnership today really do reach out to so many others in terms of how we address the global challenges," Morrison said.

The meeting comes amid the launch of AUKUS - a trilateral security pact between Australia, the United Kingdom, and the United States - announced on September 15, 2021, that will allow Australia to have nuclear submarines.

Australia has defended the move by saying it has signed the pact to secure the Indo-Pacific region.