Hainse assumed command of the Canadian Army on Thursday in a sweltering ceremony on the front lawn of Parliament.
He replaces Lt.-Gen. Peter Devlin, who is retiring after a 35-year military career.
Until recently, Hainse was deputy commander of NATO's Joint Force Command in Naples.
The change of command was the first public event for newly appointed Defence Minister Rob Nicholson, who took over Monday after more than six years in the justice portfolio.
Prior to his departure, Devlin expressed concern about keeping the army ready in an era of declining budgets. He warned last week that some of the hard-won lessons and capabilities from the Afghan war remain on "life support."
Hainse says Canada is no different from other Western armies, all of which are facing reductions.
"This is my job to make sure we do not do less with less; we're not going to do more with less. We're going to do what it takes to maintain that operational capability," he said after the ceremony.
"My job is about leadership and delivering when needed."
Testifying before a Senate committee last year, Devlin said the army faced a 22 per cent reduction to its base budget.
With no administrative fat left to cut, budget restraint was forcing him to train soldiers to a lower standard than during the Afghan war, he testified.
Last week, Devlin spoke about scrambling to hold on to capabilities paid for in "blood" during the Afghan war, including "softer skills" now considered essential to conflicts, such as surveillance and expertise in countering improvised explosive devices.
Hainse stuck closer to the government's script during in his first public outing.
The army will look at "how to do things; how do we do things better and find efficiencies," Hainse said.
The army had a massive influx of cash and equipment during the combat mission in Kandahar, and most of its new procurement projects have proceeded smoothly and quietly, unlike projects elsewhere in the military, notably the F-35 jet fighter.
The one project with a question mark is the plan to buy close-combat vehicles, essentially light tanks capable of carrying a section of soldiers into battle.
The army apparently offered up the $2-billion program as nice, but not necessary. The Harper government, however, is determined to complete the purchase.
Defence insiders say the program has yet to receive the final nod from the federal Treasury Board, and Haines said Thursday he sees no reason for it not to proceed.