MOSCOW (Reuters) - Russia plans to extend a ban on Western food imports for six months starting from early August, and may add new products to the list, in retaliation to extended European sanctions against Moscow, officials said on Monday.

European Union foreign ministers extended economic sanctions against Russia until Jan 31 on Monday, keeping up pressure on Moscow to help resolve the Ukraine conflict. "Taking into account that the European Union has extended sanctions against the Russian Federation for half a year, I ask you to prepare my proposal to the president to extend the presidential degree (on the ban) for this period," Russian Prime Minister Dmitry Medvedev told a meeting with his deputies.

Russia had been widely expected to prolong the ban beyond an Aug 8 deadline, as officials previously said the decision directly depended on the European sanctions extension.

Russia's Agriculture Ministry has started to prepare a proposal for the list of imports to be included in the ban and may add new products to the list, Mr Ilya Ananyev, the ministry representative, told Reuters. "We are preparing proposals on the list of products, its extension is not our decision," Mr Ananyev said.

The ban, which prohibits food imports worth US$9 billion from the United States, European Union, Australia, Canada and Norway, was imposed for a year in retaliation to Western sanctions on Russia over the Ukraine crisis.

But the Kremlin is unlikely to approve the addition of new products to the list, sticking to what it calls a policy of reciprocity, one of the Russian officials said.

Russia banned imports of fruit, vegetables, meat, poultry, fish, milk and dairy.