'Challenges' to Lewis and Shetland emergency tugs cover
Further meetings are to be held between four councils and the UK government about the future of two emergency tugs covering Scottish waters.
Vessels hired to carry out coastguard duties around the UK coastline were withdrawn in 2011.
But protests led to tugs returning to bases in Lewis and Shetland on a temporary basis until 31 March.
Scotland Secretary Michael Moore said "challenges" remained to putting in place appropriate measures.
He said a meeting with representatives from Comhairle nan Eilean Siar (Western Isles Council), Highland, Orkney and Shetland councils on Thursday was constructive.
Beyond 31 March, the oil and gas industry has offered to support the Maritime and Coastguard Agency by deploying its chartered vessels in emergencies off the Northern Isles.
However, a long-term solution for the Western Isles and west Highlands had still to be agreed.
The vessels provide pollution control and, in the past, have gone to the aid of private and military vessels in distress.
Mr Moore said: "We had a constructive and useful meeting in Edinburgh and continue to make good progress.
"We are also working with the oil and gas sector towards a specific solution for the Northern Isles.
"A number of challenges remain and I am grateful to everyone involved for their hard work to date. There will be a further meeting shortly which will look at the issue of future cover for the Western Isles."