Brent crude futures were down $1.53, or 1.90 per cent, at $79.04 per barrel. Prices had earlier risen to $82.30 at the start of trading amid uncertainty surrounding the talks and renewed geopolitical tensions.

US West Texas Intermediate (WTI) crude futures traded at $76.53 a barrel, down 7 cents, ahead of the contract's expiry later on Monday. The more active August contract fell 55 cents to $75.30 a barrel. There was no settlement in the US market on Friday due to a public holiday