Image copyright AP Image caption Saudi Arabia's Oil Minister Ali al-Naimi said falling prices were not good for the country, but would help stimulate global economic growth

Oil-rich Gulf states have vowed not to cut crude production, blaming speculators and producers outside the Opec group for tumbling prices.

Saudi Arabia's Oil Minister Ali al-Naimi said "the spread of misleading information and speculation" had contributed to the 40% price fall.

Speaking in Abu Dhabi, he also dismissed claims of a Saudi plot to push prices down for political goals.

Ministers from Kuwait and the UAE also said there were no plans to cut output.

Mr Naimi said that if producer countries outside Opec wanted to restrict output, "they are welcome".

"We are not going to cut, certainly Saudi Arabia is not going to cut."

Kuwait's Oil Minister, Ali al-Omair, said Opec did not need to cut production and would not consider an emergency meeting.

"I don't think we need to cut. We gave a chance to others [and] they were not willing to do so," he said during the conference in Abu Dhabi on Sunday.

In November, Opec decided to keep its target output of 30 million barrels per day unchanged, leaving the market to balance itself without the group taking action.

Price rise?

In the past, Saudi Arabia, the world's largest producer, has acted to rein in output to support prices.

The decision not to intervene this time prompted conspiracy theories, including that Opec wanted to undermine the US shale boom and that there was a political plot to reduce oil revenues earned by Russia and Iran.

Mr Naimi denied that politics played a role in the kingdom's oil policy. He said he was not happy about the falling oil price, but added: "Current prices do not encourage investment in any form of energy, but they stimulate global economic growth, leading ultimately to an increase in global demand and a slowdown in the growth of supplies."

Image copyright AP

Meanwhile, Opec's Secretary-General Abdullah al-Badri told Reuters news agency on Sunday he hoped to see a recovery in the price of oil by the end of next year.

"We hope the price would rebound by the end of the second half of 2015," he said. "We can't see the market now, we have to wait until the end of the second half of 2015 to see how the market [will] react to these low prices."

The world is expected to need less Opec oil next year as the US shale gas boom accelerates.