Moon visited one of the women, Kim Bok-dong, separately in the morning as she was ill and unable to attend the lunch.

"We survived when bullets were raining down and we'll be able to get through this," Kim told Moon, the Blue House said.

The women want Japan to take legal, binding responsibility for its actions and Kim was scornful of the 2015 payout.

"The money should be sent back to Japan," she said.

Historians said up to 200,000 girls and young women, mostly from the Korean Peninsula, served as sex slaves for Imperial Japan.

As of December, there are at least 32 surviving, according to a South Korean civic group set up to look after their rights.