Opec’s challenge - to pump more oil while keeping deal in place

During the meeting, the group is expected to raise crude output after more than a year of cutting it to stabilize once-falling prices.

The odds of the Organization of Petroleum Exporting Countries reaching a deal on Friday have increased through the week.

Saudi Arabia urges OPEC to help consumers by boosting oil supply as opposition from arch-rival Iran shows signs of wavering.

Observers say the participating countries could simply agree to stop exceeding their quotas for cutbacks, and stick to the agreed target of trimming production by 1.8 million barrels per day (bpd).

"He said Trump was partly to blame for the higher oil prices, saying the USA leader had "created difficulty for the oil market" by imposing sanctions on Venezuela and Iran".

Oil prices fell after Al-Falih's comments, with benchmark Brent crude losing as much as 2.4 percent to $72.94 a barrel in London.

The U.S. average for gasoline stood at $2.87 a gallon on Thursday. Zanganeh has said the president is to blame for high prices because of his unilateral withdrawal from the worldwide nuclear agreement.

Iran has edged away from a threat to veto any agreement that would raise output, while Saudi Arabia has put forward a plan that would add 600,000 barrels a day - about 0.5 percent of global supply - smaller than the 1.5 million increase Russian Federation proposed.

Iran had been expected to oppose any rise in crude output, but it has now signalled it may support a small increase.

Russia, which is not a part of OPEC but is the world's biggest oil producer, is also pushing to loosen supply controls introduced to prop up prices in 2017.

Some analysts believe that Saudi Arabia needs a Brent price closer to $90 to cover its domestic spending but is feeling pressure from the United States to head off rising prices by boosting output.

"We need to release supply to the market", Energy Minister Khalid al-Falih said, according to Reuters. "The geopolitical factors will play in a lot". "These prices are creating stress throughout global economy, as it is giving pain to us in India".

"They may have to add production to make up for the unrest in Venezuela and the Iranian sanctions that are ahead of us, as well as the effect in China", he said.

Oil prices fell on Thursday as crude exporters in Opec appeared to be nearing a deal to increase production.

"Essner is betting that the Vienna meeting will yield an agreement to boost production by 500,000 to 800,000 barrels a day, far below the 1.5 million barrel figure floated recently by Russia's oil minister, Alexander Novak". The paper agreement would see production increase by 1 million barrels a day to bring the group back to target.