Authorities say a sharp spike in the international price of fuel is to blame for higher prices at the pump across Victoria.

The petrol commissioner, Joe Dimasi, says the price of petrol in Singapore has reached a high of $US1.35 a barrel, representing an 11 cent per litre increase since December.

Mr Dimasi says it has resulted in most local outlets selling petrol for about $1.60 a litre.

However the high prices will not last too long.

"That should come down over the next week," he told ABC local radio.

"If you can avoid buying it at $1.599, I'd certainly advise people to do that."