Sen. Ted Cruz is urging the Trump administration to enforce international aviation agreements with the United Arab Emirates and Qatar, alleging that the Persian Gulf nations are unfairly subsidizing their state-run airlines.

In a letter obtained exclusively by the Washington Examiner, Cruz writes that UAE and Qatar are in "open violation" of so-called Open Skies agreements that allow airlines to operate internationally without government interference.

"The Gulf carriers have received an unprecedented level of subsidization," Cruz, R-Texas, wrote to Secretary of State Rex Tillerson, Commerce Secretary Wilbur Ross and Transportation Secretary Elaine Chao, in a letter dated July 17.

"This blatant disregard for our Open Skies agreements has allowed these airlines to undercut U.S. carriers, financially damaging the U.S. airline industry, jeopardizing service to small-and medium-sized communities and threatening American jobs. I know that you share my belief that American companies will not only compete, but excel in a true free market. Our government should once again stand by them and the agreements we have entered into."

The Trump administration is being pressured by three of America's largest airlines — Delta Air Lines, United Airlines, and American Airlines — to take action against the UAE and Qatar for allegedly subsidizing their state-owned airlines: Etihad Airways, Emirates, and Qatar Airways.

These same companies similarly lobbied the Obama administration to renegotiate the Open Skies agreements with Qatar and UAE, but the federal government did not take action.

In 2015, a bipartisan group of 262 House lawmakers wrote a letter asking the Obama administration to investigate Qatar and UAE for "using these subsidies and other unfair practices to distort the market in favor of their state-owned airlines."

Opponents of renegotiating the Open Skies agreements, including JetBlue, FedEx, and Atlas Air Worldwide, say these pacts promote competition and lower prices for travelers. They worry that American action against UAE and Qatar could encourage other countries to retaliate against the U.S.

The U.S. has negotiated more than 100 Open Skies agreements since the early 1990s.