The idea of an “Arab NATO” has been bandied about for years — and has always had strong Saudi support — but until now was never openly endorsed by the U.S. government. Officials said the concept fits three major tenets of Trump’s “America First” foreign-policy frame: asserting more American leadership in the region, shifting the financial burden of security to allies and providing for U.S. jobs at home (through the massive arms sales).

The president is looking for an answer to the question of how the United States can eventually hand over security responsibility in the region to the countries that are there, officials said.

Reports from the region about early discussions of the project said that in addition to Saudi Arabia, initial participants in the coalition would include the United Arab Emirates, Egypt and Jordan, with the United States playing an organizing and support role while staying outside the alliance.

The White House admits that many of the details of how the new alliance will operate remain to be worked out. The countries of the region harbor deep historical grievances and don’t agree on key issues, including the way forward in Syria. A 2015 effort by Egypt to establish a pan-Arab fighting force collapsed due to squabbling among the countries involved.