BELEK, Reuters (Reuters) - Russian President Vladimir Putin said on Monday that Russia is ready to support Syria's opposition with air strikes in their fight against Islamic State.

"I can confirm that we have established contacts with ... Syrian opposition on the battlefield which asked us to conduct air strikes," Putin said on the sidelines of the Group of 20 (G20) summit in Turkey's Antalya.

Separately, he said that only after traces of explosives are found on debris of a Russian plane that crashed last month in Egypt can conclusions about what had caused the crash be made.

(Reporting by Denis Dyomkin and Lidia Kelly; Editing by Jack Stubbs)