Australia is set to acquire hundreds of Tomahawk cruise missiles from the United States as part of the AUKUS security pact.

The Pentagon has approved the sale of 220 of the missiles at a cost of $1.3 billion in a deal that will also include technical support.

The sale of the missiles follows the announcement of Australia acquiring multiple nuclear submarines under the US-UK alliance at a cost of up to $368 billion.

Deputy Prime Minister Richard Marles said Australia would be working closely with the US to get more missile capability.

“It’s a really important part of what we need to be doing with our posture, which is to have a greater ability to project,” he told Nine’s Today program on Friday.

“Making sure we have longer-range strike missiles is a really important capability for the country. It enables us to be able to reach out beyond our shores further and that’s ultimately how we are able to keep Australia safe.”

Defence Industry Minister Pat Conroy said the missiles were able to be fired from the US Virginia-class submarines Australia would be acquiring under the AUKUS deal.

“We certainly want the best possible capability for the Australian Defence Force so that includes the ability to strike opponents as far away as possible from the Australian mainland,” he told ABC TV.

“The cruise missiles are a critical part of that, as are the submarines that launch them.”

The announcement of the missiles follows criticism from former Labor prime minister Paul Keating about the submarine deal.

Opposition Leader Peter Dutton said despite the critiques, the coalition would be backing the security partnership.

“We’ve all been on the end of Paul Keating sprays but it was a special effort this week,” he said.

“It is in our country’s best interests. That’s why we negotiated AUKUS and we will do everything we can to help the government get through the family feud.”

Mr Marles said the attacks on the AUKUS deal were not surprising, but the submarine agreement was the right decision.

“We’ll make sure we deal with all that but at the end of the day, we are focused in speaking to the Australian people as we are with our own party room,” he said.

By Andrew Brown in Canberra