Cathal Geoghegan made the remarks to more than 900 business and political leaders at an event in Belfast as Stormont continues to be effectively collapsed.
Senior civil servants have been leading government departments with limited powers since the DUP withdrew their ministers in February 2022 in protest at post-Brexit trading arrangements.
Mr Geoghegan spoke of frustration at the stalemate, and said a fully-functioning, stable executive is “our most urgent priority”, but emphasised it must be one that lasts.
“Tackling Northern Ireland’s fiscal challenges is the region’s greatest opportunity to ensure stability through public sector and societal transformation for decades to come,” he said.
“The most recent budget set by the secretary of state was uncomfortable reading but without discussion and answers about how Northern Ireland is funded from Westminster, it is a challenge we will face on repeat.
“At NI Chamber, we have long argued that a restored executive must not only be capable of making tough decisions, but it must also be sustainably funded, recognising the issue of need.”
He went on: “It’s frustrating that for yet another year, at this time, indeed on this stage, we must ask ‘when do we get our government back?’
“We are fast approaching 650 days without an executive – that’s a milestone no-one in this room wants to see. Because for all of us, that’s vital time lost for decisions about spending and overdue reforms on health, climate change, planning and so much more.”
Addressing representatives of the five largest political parties in Northern Ireland at the black-tie event in the International Convention Centre (ICC), Mr Geoghegan proposed a partnership approach to the in-tray of waiting issues.
“The membership of NI Chamber, the leadership represented here tonight, is an unrivalled resource and it’s ready to start co-designing and co-delivering on workable, innovative new ideas, right now,” he said.