Asked how he could comment on Macron's claims, Tusk told reporters that G20 leaders should help Japanese Prime Minister Shinzo Abe, whose country holds the presidency of the summit, with a final declaration instead of threatening to boycott it.
Earlier in the week, Macron said that the climate change was a "red line" issue for the G20 summit and warned that France would not sign a final declaration if it did not include the leaders' strong support for climate protection measures.
The Osaka G20 summit kicked off earlier in the day and will last through Saturday. The digital economy, data use security, energy and trade efficiency are topics that are high on the forum's agenda.