Senator Jim Risch, Republican of Idaho and the chairman of the panel, was more muted. In a brief statement, he said he was “reviewing and analyzing the legal justification for this action and the associated implications.”

American companies will now be able to sell $8.1 billion worth of munitions in 22 pending transfers to the three Arab nations. The two gulf countries are waging an air war in Yemen that has come under sharp criticism from Congress and human rights organizations. Some of the munitions would take years to produce and deliver, so it is not obvious how those sales are consistent with the argument that the exports are to address an immediate crisis with Iran.

A part of the arrangement involves a transfer of munitions from the United Arab Emirates to Jordan that has nothing to do with Iran, said one person briefed on the decision.

Secretary of State Mike Pompeo had pushed hard for the move, over the objections of career Foreign Service officers and legislators. “These sales will support our allies, enhance Middle East stability and help these nations to deter and defend themselves from the Islamic Republic of Iran,” Mr. Pompeo said on Friday afternoon.

The acting defense secretary, Patrick Shanahan, described the troop deployment as a “prudent defensive measure and intended to reduce the possibility of future hostilities.”

In a statement, he said the deployment would consist of a Patriot missile-defense battalion — which is already there and will see its deployment extended — additional intelligence, surveillance and reconnaissance aircraft; an engineer element to improve protection measures for military personnel; and a fighter aircraft squadron. The warplanes are able to carry out offensive as well as defensive operations.



The president reached his decision after a meeting on Thursday at the White House with top national security aides, and concluded that a small increase would be sufficient.

