The Stena Line ferry company has insisted it is "fully committed to supporting and developing" its terminal at Fishguard in Pembrokeshire.
Eight days ago it announced it had dropped a £5m plan to replace the flexible ship-to-shore bridge that allows vehicles on and off.
Local councillors described it a "worrying time" for the town.
The new commitment to the port came in an updated statement on Thursday.
The ferry operator had already invited tenders for the work to replace the Linkspan bridge on the Fishguard to Rosslare route.
But earlier this month it cancelled the plan and said it did not now "have a timescale for future developments".
The decision followed Stena's scrapping of plans for a marina and apartments at the Fishguard terminal in January to "focus all resources on our core business".
Local councillor Pat Davies said she was deeply concerned by Stena's decision not to proceed with the new ship-to-shore connection and that the company could pull out.
"I can't really bear to think about it actually and other people in our community feel the same," she said.
"There is no alternative employment in our area to pick up that shortfall."
Transport expert Dr Andrew Potter from Cardiff University said the port could struggle to survive without the funding.
"Stena Line has to look at the Holyhead route which is the main Irish sea route," he said.
"It may be that they are reserving their funds for Holyhead at the expense of Fishguard."
In response Stena Line has reissued its statement from earlier this month with an amended last line.
It said: "Stena Line does not have a timescale for possible future developments but remains fully committed to supporting and developing its ferry services at Fishguard."