The Highways Agency has stopped treating motorway hard shoulders in England and salt ordered from abroad is not due to arrive until 21 January.
The Highways Agency's David Grunwell said: "We've got sufficient supplies to treat the strategic road network at the moment given the current Met Office forecast.
"We're confident that we'll get the supplies that we need. Central government are now providing advice nationally to salt suppliers and they are advising where the priorities are greatest across the country."
The AA said it raised concerns about salt supplies with the Local Government Association (LGA) before Christmas.
Spokesman Paul Watters said councils had reduced stocks by 250,000 tonnes during the past 10 years.
The Conservatives said the decision to ration salt was "an admission of utter failure" and plans should have been made earlier.
Gordon Brown has pledged the UK's gas supplies will not run out during the current cold snap, and that road salt will get to "where it is most needed".
The PM acknowledged the current "worrying and frustrating" situation but said agencies were working together to keep the public "safe and warm".
National Grid has lifted a "gas balancing alert" put in place on Saturday, after warning of a potential shortfall in supplies.
These alerts help the market to consider increasing gas supplies, and encourage electricity providers to use alternative fuels such as coal.
National Grid said the third alert was not due to the weather conditions but problems in the Norwegian gas fields. The alert was lifted at 0600 GMT on Sunday.
A spokesman said: "The market responded to the alert. More supplies came through."
Charities have called for cold weather fuel payments to pensioners to be increased to prevent the death rate soaring.
WEATHER AND TRAVEL INFO
Get the latest on school closures and travel problems via your
Details of motorway and local road closures and public transport disruption are available at
BBC Travel News
For advice on handling difficult driving conditions, see the
For information about severe weather warnings, see the
For information about staying healthy in the current cold snap, see the
NHS Winter Health
The Red Cross has said it was having one of its busiest periods in 30 years as volunteers help the emergency services and provide assistance to people in need.
Elsewhere, a man has died after falling through ice which was covering the River Tees in Stockton.
The man, who has not been named but was in his mid-50s, was walking his dog close to the Tees Barrage on Sunday afternoon.
Twenty-six other people have died since the cold snap started, including a 90-year-old woman who froze to death in her garden near Barnsley and a woman, 42, who died after being found near shops in Newcastle.
Police are also searching for missing mountain-walker Steven Bailey, 51, from Ambleside, Cumbria. He was last seen on Tuesday in Windermere in the Lake District.
Kent Police has called in the Army to help get supplies to snow-bound homes in the county.
Easyjet has had to cancel a number of services to Geneva in Switzerland, while all its services to the Polish city of Krakow have been cancelled - due to bad weather on the continent.
British Airways has cancelled "a number" of flights on Sunday, and advises passengers to check its website before heading to the airport.
There was better news on the railways, with the Association of Train Operating Companies saying most operators had returned to normal timetables - although 10 companies continue to run revised services.
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