"I'd love to have them back; it was a mistake to throw them out."

Trump clearly states his desire to bring Russia back into the G8.

"It wasn't a question of liking Russia or not liking Russia, it was the G8. I think Putin would be happy to come back," Trump said 

Russian Reply: 

The Kremlin believes that the G7 has lost its relevance because it unites countries that are not leaders in economic growth - Dmitry Peskov