President Donald Trump is poised to meet with the heads of American Airlines Group Inc. (AAL.O), United Airlines Holdings Inc. (UAL.O) and Qatar Airways to discuss competition issues amid a long-running feud pitting the U.S. carriers against their Persian Gulf rivals, people familiar with the matter said.

Vice President Mike Pence will also attend the meeting Thursday afternoon with American Chief Executive Officer Doug Parker and United’s Oscar Munoz, said the people, including a White House official, who asked not to be named ahead of the private discussions. American, United and Delta Air Lines Inc. have long argued that government subsidies enable Qatar Airways, Emirates and Etihad Airways to compete unfairly.

The White House meeting comes two weeks after Trump hosted the emir of Qatar at the White House. Qatar Airways CEO Akbar Al Baker will also attend the Thursday meeting, as will Fred Smith of FedEx Corp., Robin Hayes of JetBlue Airways Corp. and Bill Flynn of Atlas Air Worldwide Holdings Inc., a freight and charter company. Those three U.S. companies have opposed American, United and Delta on the subject of the Persian Gulf carriers.

The U.S. and Qatar have recently been at odds over whether Qatar Air’s stake in Air Italy is meant to undercut U.S. competitors, despite a previous deal between the nations. U.S. Secretary of State Mike Pompeo said in April that he was “personally engaged on this issue and we are working to make sure that every party to those agreements complies with every element of those agreements.”

Delta CEO Ed Bastian isn’t attending the meeting because he’s traveling abroad. The Atlanta-based airline reaffirmed this month that it is considering an investment in Italy’s Alitalia.