HAMBURG (BLG) - Australia will press ahead with a missile defence programme to protect its forces, but a US shield system is not appropriate, Prime Minister Malcolm Turnbull said.

The Terminal High Altitude Area Defence, or Thaad, system mentioned in recent briefings is "not really suitable for our situation", Turnbull told reporters at the Group of 20 Summit on Friday (July 7).

The meeting in Hamburg has been overshadowed by North Korea's first successful launch last week of a missile capable of reaching at least part of the United States.

"The answer in respect of North Korea is the de-nuclearisation of North Korea and for it to stop its reckless conduct, its reckless and provocative conduct," Turnbull said. "The nation with overwhelmingly the greatest leverage over North Korea is China. And so we look to China to bring North Korea to its senses."

The Australian government is bolstering its weaponry and military forces in response in part to the "growing threat posed by ballistic and cruise missile capability" and their proliferation in the Indo-Pacific and Middle East regions, the Department of Defence said in a 2016 report.

While the threat of an intercontinental ballistic missile attack on Australia is "low", longer-range and submarine-launched ballistic and cruise missiles could threaten Australian territory, and shorter-range ballistic and cruise missiles pose a threat to deployed forces.

"We're developing missile defences," Turnbull said. "The focus is on protecting our forces both at sea and on the ground - our deployed forces in the field."