UK government budgets for offshore wind power are unlikely to support Scotland's ambitions to develop the industry, the first minister has said.
Nicola Sturgeon called on the government to guarantee funding which would allow offshore wind to be delivered on a far greater scale.
She said: "The UK government must now show greater ambition."
The Department of Energy and Climate Change said there was "huge potential" for future deployment in Scotland.
Only one Scottish offshore wind farm received a share of £260m set aside for projects from 2016-2018 and beyond.
Two major offshore wind farms were refused the 15-year Contracts For Difference (CFDs), which guarantee a price for the power generated.
The first minister said the decision had left uncertainty over their future development.
Ms Sturgeon was speaking ahead of a visit to Whitelee wind farm in East Renfrewshire - Scotland's largest onshore development.
She said: "Scotland has made huge progress in renewables deployment in Scotland, generating enough renewable energy to meet 44% of Scotland's annual electricity demand, generating millions of pounds of community benefit, and displacing an estimated 12 million tonnes of carbon dioxide across the UK.
"Scottish onshore wind is now considerably cheaper than new nuclear, thanks to sustained support and large-scale deployment of projects such as Scottish Power's Whitelee development.
"We are already seeing cost reductions in offshore wind but the scale of growth planned for the sector will be a key driver to delivering further cost reductions for the long-term benefit of consumers."
The first minister added: "It is essential that the UK government provide confidence to the offshore wind industry that sufficient money will be available in future allocation rounds to allow the sector to move forward with assurance and enable costs to be further reduced.
"Without this ambition Scotland risks missing the opportunity to cement the growth of an industry, with significant supply chain benefits, while decarbonising our energy supply."
WWF Scotland director Lang Banks said the first minister was right to highlight the need for "greater clarity and ambition in the UK for offshore wind power".
He added: "Onshore renewables in Scotland have gone from strength to strength over the years, helping to cut carbon, create jobs and keep the lights on.
"However, if we are to be able to fully harness our offshore wind potential then the next UK government must provide a stable and sustained funding stream and clear volume signals for the coming decade."
A spokeswoman for the Department of Energy and Climate Change said: "The UK is the world leader in offshore wind and has huge potential for future deployment, including in Scotland.
"We announced on Thursday the first allocation round for Contracts For Difference, which included a contract for a new Scottish offshore wind farm.
"Available funding for CFDs for renewables and carbon capture and storage in future years could rise to over £1bn per year by 2020/21. The budget for the next allocation round will be confirmed later this year."