WASHINGTON DC: President Donald Trump is expected to host U.S. oil companies at the White House on Tuesday to discuss expanding refining capacity, after accusing refiners of gouging consumers as gasoline prices remain above US$4 a gallon.

Trump has called for a Justice Department investigation and urged companies to use their bumper earnings to lower gasoline prices, which surged amid the ongoing conflict with Iran. The White House says the gathering on September 1 will also celebrate industry efforts to keep the market well supplied.

Companies received invitations only late last week, with few details about the event or who else would attend, according to people familiar with the plans. Some companies have considered whether sending their CEOs could lead to an uncomfortable encounter with Trump.

"You want to be at the table, but you also have to think about what could happen once you're there. You don't want your CEO to be embarrassed," said one company official involved in advising what executives would attend.

Another company official said the meeting would provide an opportunity to discuss issues including the administration's biofuel policy and the Jones Act, which can affect the cost and availability of fuel shipments between U.S. ports.

"There are certainly concerns about the optics, but you also don't want to miss an opportunity to have a direct conversation with the president about issues that are important to the industry," the official said.

Exxon CEO Darren Woods drew Trump's ire at a White House meeting in January after describing Venezuela as "uninvestable" in its current form. Trump subsequently said he was "inclined to keep Exxon out" of Venezuela and accused the company of "playing too cute."

Exxon, the country's third-largest refiner by capacity, was not invited to the meeting, according to sources. The White House did not comment on the attendee list, while Exxon did not respond to requests for comment.

Companies invited include Marathon Petroleum, Delek US Holdings, Chevron, PBF Energy and Valero Energy, according to people familiar with the plans. None responded to requests for comment about concerns over attending.

The White House said the meeting would focus on expanding U.S. refining capacity, arguing that years of Democratic policies led to refinery closures and discouraged investment in new facilities and expansions. A White House official said the country is operating at nearly 100 percent of its existing refining capacity, and the administration is seeking "concrete, near-term steps" to increase capacity and lower gasoline prices.

The meeting also comes as the administration works to increase flows of Venezuelan crude to U.S. refineries.

Gasoline prices surged after the Iran conflict began in late February and climbed above $4 a gallon in the spring. Heading into Labor Day weekend, prices are at their highest ever for this point of the year, while the American Automobile Association says August is on track to be the most expensive August on record.

U.S. refiners recorded strong second-quarter profits as gasoline and diesel margins increased. Marathon, Phillips 66 and Valero reported combined second-quarter profits of $12.6 billion.