OSLO, Aug 10 (Reuters) - Latvian gas trader Latvijas Gaze , partly owned by Gazprom, said it was unable to supply enough gas for Latvia to meet an Aug. 31 goal on filling storage and said the responsibility lay with the country's state utility.

While the European Union has told its member states to fill gas storage to 80% full by Oct. 1 to try to ward off a shortage of fuel over the peak demand winter months, Latvia also has a national requirement for public gas suppliers to store enough gas for households.

The parliament set the requirement last month and at the same time enacted a ban on gas imports from Russia effective from the start of 2023.

Latvijas Gaze, which buys most of its gas from Russia under long-term contract with Gazprom, said on Wednesday it would not be able to meet the Aug. 31 deadline and that state utility Latvenergo should by law assume responsibility for supplies.

Latvia's government said, however, the nation had enough natural gas in storage to meet households' needs for the upcoming heating season, the BNS news agency reported.

It said it had reserved for domestic use natural gas held by Latvijas Gaze at the country's underground Incukalns storage, and that, together with other supplies, this would be sufficient, BNS reported.

Latvenergo separately told BNS it had the capacity to take over Latvijas Gaze's portfolio of some 350,000 households.

Latvijas Gaze is the largest supplier of gas to households in the Baltic state with a population of 1.9 million, and it also trades gas in neighbouring Lithuania and Latvia, as well as in Finland.

Russia's Gazprom is Latvijas Gaze's largest owner with a 34% stake, followed by infrastructure investment fund Marquerite Gas II with 28.97% and Germany's Uniper with 18.26%.

Latvia's Incukalns gas storage, which has capacity to store up to 21.8 TWh (terawatt-hours) of gas, is 54.3% full, according to Gas Infrastructure Europe.

The largest consumers of natural gas in Latvia are combined heat and power plants, district heating companies and industries. (Reporting by Nerijus Adomaitis, editing by Terje Solsvik and Barbara Lewis)