Foreign traders have collected 1.8 billion cubic meters (bcm) of natural gas in underground storage in Ukraine ahead of the winter season, Ukraine's energy ministry said on Wednesday.

State-owned energy company Naftogaz said last month that foreign customers could use more than 10 bcm of storage of the country's around 30 bcm capacity, mostly in the country's west, which is far from the front lines.

"European underground gas storage facilities are about 94% full. Therefore (gas transport company) Ukrtransgaz's gas storage capacities are becoming even more attractive to European traders," Energy Minister German Galushchenko said on the Telegram messaging app.

"This is a good sign for us and for Europe, because together we are strengthening the continent's energy security," he said.

Traders told Reuters last month that European gas traders had begun storing natural gas in Ukraine to take advantage of lower prices and available capacity there, regardless of the risks from the ongoing war.

Since Russia's full-scale invasion of Ukraine in February last year, the European Union has sought high levels of gas storage to compensate for reduced Russian supply, especially during the peak-demand winter months.

Ukraine reported last month that it had built up around 14 billion cubic metres (bcm) of gas in its storage facilities and that it did not plan to import gas in the 2023/24 heating season.

Ukraine uses gas mostly for heating, and says it has nearly completed repairs of its power systems following Russian air strikes on energy infrastructure last winter.

Russia's campaign of frequent missile and drone attacks last winter resulted in power cuts and scheduled blackouts to limit energy use, leaving towns and cities in darkness for hours at a time. (Reporting by Pavel Polityuk, Editing by Timothy Heritage)