Australia will have better access to US military weapon stocks and will start building its own missiles after high-level strategic talks in Brisbane.
Defence Minister Richard Marles said the agreement marked a "very, very significant" step in the allies' relationship after he and Foreign Minister Penny Wong met their US counterparts on Saturday.
"We are very grateful to the efforts which have been undertaken by the Biden administration in respect of defence export control legislation and creating a more seamless defence industrial base between our countries," he said.
Under the plan, Australia will start producing guided, multiple-launch rocket systems, known as GMLRS, within two years.
The US was also "racing" to accelerate Australia's access to priority military weapons through a streamlined acquisition process, US Defense Secretary Lloyd Austin said.
Australia would get its hands on, and could overhaul, critical US and US-sourced munitions, he said.
"Our meetings today reaffirm the strength of our unbreakable alliance and the strategic alignment between our countries has never been greater," he said.
The plan has been driven by the Russian war in Ukraine, which has highlighted Western nations' lack of ammunition stocks.
With US Secretary of State Antony Blinken, the leaders also discussed climate change and clean energy, China, space, aid for the Pacific and Julian Assange's looming extradition to answer US charges.
Mr Blinken emphasised Assange's serious charges related to one of the US's largest intelligence compromises, placing named human sources at grave risk.
"I say that only because just as we understand sensitivities here, it's important our friends understand sensitivities in the United States," he told reporters in Brisbane.
The meeting was overshadowed by a helicopter crash and the desperate search for the four personnel in Queensland.
The Australian Army helicopter hit waters off Hamilton Island during joint military exercises late on Friday.
The US officials said the helicopter crash was constantly on their minds throughout the meeting.
"'I've told the deputy prime minister (Mr Marles) that whatever he needs, we stand ready to provide assistance," Mr Austin said.
The accident served as a stark reminder of the risks faced and courage shown by those serving their country, Ms Wong said.
The 33rd Australia-United States Ministerial Consultations meet was the first since Australia's agreement to secure nuclear submarines under the AUKUS security deal was announced.
A small group of Republicans is threatening to block the agreement, citing concerns the US Navy will be left short.
Mr Marles said he was absolutely assured by Mr Blinken, Mr Lloyd and US lawmakers of a bipartisan commitment to Australia acquiring and operating nuclear-powered submarines.
Australian naval officers were being trained at the US Navy's nuclear power school and there would be an "increased tempo" of US nuclear-powered submarines visiting Australian shores, he said.
"We couldn't be happier with the progress in which the optimal pathway is being walked," he said.
Mr Blinken said in a challenging global climate, it was important for like-minded nations to work in partnership.
The two countries shared a commitment to advance a free, open, secure, prosperous, resilient and connected Indo-Pacific, he said.
"As President (Joe) Biden has said, the United States has no closer normal, reliable ally than Australia," he said.
Mr Marles and Mr Austin are due to travel to north Queensland to meet Australian and US troops taking part in military drills as part of the Talisman Sabre exercise.
The trip was planned before the crash on Friday night.
