UPDATE 3-Trump rails against high oil prices, OPEC pushes back

* OPEC's Barkindo: output cuts helped rescue oil industry

* Futures drop on Trump tweet

* Concern about renewed Iran sanctions driving bullish bets (New throughout, adds comments, details on Saudi Arabia, inventories; adds two bylines and DUBAI dateline)

WASHINGTON/DUBAI, April 20 (Reuters) - U.S. President Donald Trump accused OPEC on Friday of "artificially" boosting oil prices after a year-plus pact that has slashed global crude inventories, drawing rebukes from oil-producing countries as prices dipped following his remarks.

"Looks like OPEC is at it again. With record amounts of Oil all over the place, including the fully loaded ships at sea. Oil prices are artificially Very High! No good and will not be accepted!" Trump wrote on Twitter.

His tweet came shortly after Saudi Arabian officials said they remained far from reaching their goal in reducing a three-year global supply glut. Earlier this week, three officials from the country, the world's leading producer, told Reuters they would be happy to see oil hit $80 or $100 a barrel.

This week, oil prices rose to levels not seen since late 2014, and the expectation is that the cartel will continue to restrain supply through the end of this year.

Several members of the Organization of the Petroleum Exporting Countries responded to Trump's tweet, saying oil prices were not being artificially inflated.

The group is slated to meet in June to decide its next steps after reducing output since January 2017 along with other producers including Russia, aiming to reduce a glut that had sent prices into a tailspin.

Trump gave no details on what action his administration might take regarding oil or OPEC, and the White House did not immediately respond to a request for comment.

OPEC's landmark agreement with other producers cut production beginning in 2017, and oil prices have surged to 3-1/2 year highs, with U.S. crude recently nearing $70 a barrel. The deal could potentially extend into 2019.

OPEC Secretary General Mohammed Barkindo said the agreement had halted the collapse in global oil prices, and said the group was a friend of the United States with an interest in its prosperity.

The pact is now "on course to restore stability on a sustainable basis in the interest of producers, consumers and the global economy, Barkindo said.

OPEC's output fell in March to an 11-month low, according to a Reuters survey.

This week, crude futures Brent and U.S. West Texas Intermediate (WTI) hit their highest levels since November 2014 earlier, with Brent touching $74.75 and U.S. crude $69.56 per barrel, on tighter supply and rising demand.

That has raised fuel costs, with average U.S. prices for gasoline hitting $2.75 a gallon on Wednesday, according to motorist advocacy group AAA, up more than 30 cents from a year earlier.

Trump is just trying to relate to his base when it comes to the retail gasoline prices, so hes blaming OPEC for this," said Josh Graves, senior market strategist at RJO Futures in Chicago.

Following Trump's tweet, Brent futures were at $73.04 per barrel at 10:14 a.m. EST (1414 GMT), down 73 cents from their last close. WTI futures were down 61 cents at $67.68 a barrel.

Beyond OPEC's supply management, crude prices have also been supported by expectations that Washington will re-introduce sanctions on OPEC-member Iran. Hedge funds and other speculators currently hold a record level of bullish bets in global benchmark Brent, on expectations of further price rises.

"Trump's concern about high oil prices could make renewed Iran sanctions somewhat less likely as this would tighten the oil market even further," said Carsten Fritsch, oil analyst at Commerzbank AG in Frankfurt, Germany.

Energy ministers from the United Arab Emirates and Iraq, two OPEC members, also rejected the notion that prices were too high.

The U.S. government cannot legally influence oil prices other than through releasing oil from its strategic reserves which it has done occasionally, most recently last year in the wake of Tropical Storm Harvey. (Reporting by Susan Heavey in Washington, Rania El Gamal in Dubai, Alex Lawler in London, Stephanie Kelly and Scott DiSavino in New York; Editing by Chizu Nomiyama, Jeffrey Benkoe, Frances Kerry and David Gregorio)