The firms behind proposals for the European Offshore Wind Deployment Centre (EOWDC) off the coast of Aberdeen said they were "disappointed" at the delay and called on ministers to announce their decision as early as possible in 2013.
Plans were first lodged for the renewables project some 16 months ago, but the Scottish Government is unable to say when a decision is due.
American tycoon Mr Trump has threatened to halt plans for a hotel at his new golf course on the Menie Estate, which would have a view of the wind farm should the development – sited around one mile from the coast – be given the go-ahead.
The project has led to an increasingly bitter war of words between Mr Trump, now a vociferous opponent of wind power in Scotland, and First Minister Alex Salmond.
Wind farm project spokesman Iain Todd said: "Assuming that there is no announcement on the 31st of December, the project partners are disappointed that no decision has been made in 2012 and we hope that it will be made as early as possible in 2013.
"The EOWDC is a strategically important wind project for the north-east's economy and Scotland's ambitions to be a leader in offshore wind power, and we believe that a strong case has been made to the Scottish Government for a positive consent decision."
The £230 million project is a joint venture by Vattenfall, Technip and Aberdeen Renewable Energy Group (Areg).
The 11-turbine plan is currently being looked at by Marine Scotland, after which it will be passed to ministers for a final decision.
The developers claim sites like the EOWDC could be worth £7 billion to the UK economy and that the new turbine models planned for the wind farm will increase competition in the field and drive down the cost of generating offshore wind energy.
However, the site has been plagued with controversy since the planning application was submitted in August 2011.
The American businessman claims he has been betrayed by Alex Salmond after receiving assurances that no wind farms would be built near his resort.
Mr Salmond hit back by claiming a decision to spend millions of pounds in Scotland "does not imply ownership" of the country.
Commenting on the delay to the planning application, a spokesman for the Trump Organisation attacked the First Minister again, saying: "Mr Salmond's personal meddling with the application and his mad obsession to build thousands more turbines have kept this losing proposition alive for too long. "
A Scottish Government spokeswoman confirmed the application was being considered by Marine Scotland, but could not say when a decision would be reached.
Organisations including Scottish Natural Heritage and RSPB Scotland initially raised concerns over the application alongside Mr Trump, but have since dropped their opposition.