Belfast Council says its goal of attracting £1bn worth of new property investment to the city by 2021 remains achievable.
So far, a fifth of the total has been reached in two years.
Part of the sales pitch to overseas investors is how a 12.5% corporation tax rate might drive growth, but the policy is delayed due to the collapse of Stormont.
Commercial estate agents also suggest Brexit is an additional challenge.
Speaking on BBC Radio Ulster's Inside Business programme, Brian Lavery of agents CBRE said: "We have seen good growth and interest in Belfast over the past five or six years.
"But we have certainly had headwinds this year with Brexit and the Northern Ireland Executive not sitting.
"That creates a lack of confidence in the market and does us no good whatsoever."
Belfast Council has been promoting the city at the MIPIM property conference in Cannes for the last number of years, targeting £1bn of investment and seeking to deliver 1.5m sq ft of additional Grade A office space.
A council spokeswoman said: "The 2021 target of £1 billion is on its way to being met."
She added that 529,000 sq ft of Grade A accommodation is currently in construction, with a further 700,000 sq ft due to start by the end of the year.
The Department of International Trade and Invest NI are also promoting seven development projects in Belfast to investors, including the site of the former Sirocco Works.
You can hear more on BBC Radio Ulster's Inside Business on Sunday at 13:30 GMT.