The government has instructed gas suppliers to line up reserves in neighbouring countries equivalent to 15% of the country's annual consumption of 35 terrawatt hours and to secure additional options for non-Russian gas of around 6 terrawatt hours, a fifth of winter consumption.

Switzerland does not have it own gas storage capacity.

"Regional (gas) companies have now reached between 75 and 100% of the target for building up gas reserves in gas storage facilities," the paper quoted Thomas Hegglin of the Swiss Gas Industry Association as saying.

The regional utilities were also on track to secure the envisioned options by November, he added.

Switzerland gets its gas via trading hubs in neighbouring countries in the European Union, so disruptions there would also affect Switzerland.

Switzerland has relatively low demand for gas, which covers around 15% of its total energy consumption. Around 42% of the gas is used to heat households, and the rest in industry and the service and transport sectors, according to government data.

Just under half of Swiss gas imports come directly or indirectly from Russia, the government has said.