France, Germany and Poland have become "permanent" targets for Russian disinformation attacks in the run-up to European Parliament elections this week, a senior EU official said Tuesday.

The European Union has repeatedly warned while heading into the June 6 to June 9 vote that Russia would ramp up disinformation campaigns in the 27-country bloc.

"There are three big countries under permanent attack (from Russia). And it's France, it's Germany, and it's Poland," said EU commissioner Vera Jourova, pointing to work by the European Digital Media Observatory.