Prime Minister Scott Morrison will pledge $3 billion towards much-needed infrastructure in Pacific nations as part of a frank admission Australia has sometimes taken its neighbours for granted and amid concerns that China is building its influence on Australia’s doorstep.

In what he badges a "step-up to the Pacific", Mr Morrison will on Thursday also announce the establishment of an Australian Defence Force mobile training team that can travel to Pacific nations to help them with skills including infantry fighting, peacekeeping and disaster response.

The announcements in a speech to soldiers in Townsville will be widely read as aiming to edge out growing Chinese infrastructure-building in Pacific nations and will come shortly after Foreign Minister Marise Payne arrives in Beijing for talks that signal a thaw in the year-long diplomatic frostiness between the two countries.

"Australia has an abiding interest in a south-west Pacific that is secure strategically, stable economically and sovereign politically," Mr Morrison says, according to speech notes provided by his office.