"We'll do whatever we have to to make things work.''
He said NZ Aid would fund charter boats to transport electoral commission staff and supplies to remote locations.
The Australian Defence Force is sending about 200 troops, four helicopters and two B350 King Air aircraft.
PNG has been racked with greater political instability than usual in the past year.
The encumbent, Peter O'Neill, was sworn in again as Prime Minister yesterday for the third time after a Supreme Court ruling that former Prime Minister Sir Michael Somare was the legitimate prime minister.
There are questions as to whether that swearing in was legitimate because Parliament has already been prorogued ahead of the dissolution of Parliament for the elections.
Mr O'Neill took over last year during a lengthy absence of Sir Michael through illness.
The police last week arrested the Chief Justice and charged him with sedition for a judgment in favour of Sir Michael.
Mr McCully said it was important that the people of PNG had confidence in the outcome of the elections.
New Zealand would also provide a small team of election monitors, Mr McCully said.
"Both New Zealand and Australia are pleased to help a Pacific neighbour undertake a successful general election - it is important that we assist in whatever way possible.''