Saudi Arabia’s oil minister has rejected claims that the kingdom is intent on pushing prices lower, saying the sharp falls were a “temporary” problem and not driven by political will.

The comments from Ali al-Naimi yesterday initially provided support for the oil price, which has fallen 45 per cent since mid-June to five and a half year lows. Brent crude, the international oil benchmark, rose to $64.22 a barrel, but fell in afternoon trading in the US to $60.40, down 78 cents.

“I am optimistic about the future,” Mr Naimi said. “What we are facing now and what the world is facing is a temporary situation and will pass.” Mr Naimi blamed the falls on a rise in non-Opec supply at a time when demand was slowing down amid weaker global economic growth. But he said the market “must not forget the negative role of speculators” in causing volatility.