A decision to leave a civilian university degree and walk through the front door of Defence Force Recruitment (DFR) has resulted in Lieutenant Jacob McLean leading the construction of new infrastructure in Papua New Guinea during Exercise Puk Puk.

Engineers from the Papua New Guinea Defence Force (PNGDF), Australian Army and British Army are working together to increase bonds, build relationships and develop trade skills while improving existing infrastructure at the Goldie River Training Depot near Port Moresby.

Lieutenant McLean, from Green Point on the NSW mid north coast, is overseeing the construction of a new classroom with the contingent's engineers.

"Here we're constructing a classroom for the field engineer wing," Lieutenant McLean said.

"We've come over for Exercise Puk Puk to tie in with the PNGDF and conduct minor infrastructure to further develop that longstanding relationship that we have with PNG."

As well as the construction of a new classroom, Ex Puk Puk includes construction of an inert demolition range and the renovation of the guardhouse at the depot, as well as other minor works.

Although this is the first overseas task for Lieutenant McLean, he's familiar with some of the PNGDF soldiers taking part on Ex Puk Puk.

"I actually completed my Regimental Officer Basic Course with Lieutenant Desmond Reuben, from the PNGDF," Lieutenant McLean said.

"It's good to see someone you haven't seen in about a year and a half. It's good to tie back in.

"It really enhances that point that the relationships that we built throughout our careers are going to be long-lasting."

Lieutenant McLean was mid-way through an environmental science degree when he decided to visit his local DFR office.

"In 2018 I went to DFR. By early 2019 I had a start date for Kapooka, and DFR called me up about an officer selection board (OSB)," he said.

"I went to the OSB and they said, 'We think you have what it takes to become an Army officer. You start at Royal Military College (RMC) next month'."

Graduating from RMC as a general service officer, Lieutenant McLean was posted to the 3rd Combat Engineer Regiment as Construction Troop Commander.

"I didn't expect to get Construction Troop Commander because I am a combat engineer, not a civil engineer, but I've been really lucky," Lieutenant McLean said.

"The challenges that you are faced with as Construction Troop Commander; it's definitely something different to what you would face in a combat engineer squadron.

"It's great to have jobs where you can see results like this."

Exercise Puk Puk has been an enduring commitment to PNG since the early 2000s.