Kyiv - Russia has hit at least half of Ukraine's thermal generation capacity and caused billions of dollars of damage in attacks since Oct. 10, but not all stricken power units have stopped working completely, Ukraine's energy minister said on Friday.

Herman Halushchenko told Reuters in an interview that 30-40% of overall national power infrastructure had been hit in attacks that he depicted as intended to destroy Ukraine's energy system - a goal that he said had not been achieved.

"It's quite a lot of capacity. I can tell you that it's... at least half of thermal generation capacity, even more," he said, when asked about the scale of the damage.

"This week, they targeted a number of thermal generation (plants)," Halushchenko said, adding that Ukraine had lost 4000MW in generating capacity as a result of those attacks.

Russia stepped up its aerial attacks on Ukraine last week using missiles and drones to target Kyiv, other major cities and energy infrastructure.

"We see that they targeted a number of new (facilities), but also they shelled (facilities) which had been already shelled before to destroy them absolutely," Halushchenko said.

He said that electricity imports could be one of the options Ukraine pursues to get through the crisis, and that some traders had already started negotiations with suppliers.

(Reporting by Max Hunder; writing by Tom Balmforth; editing by Timothy Heritage)