NORFOLK, Va. ― The U.S. is figuring out a game plan to send troops to support Saudi Arabia following Iranian airstrikes on its oil fields, but how many, their capabilities and where they’ll come from won’t be announced until later this week, a senior official told reporters Tuesday.

Following the Pentagon’s Friday announcement that it would deploy forces as a deterrent to Iran’s recent antagonizing of a U.S. ally, senior leaders are looking at options for a deployment, the official said, and hoping for a contribution from key European allies.

“At this point, we’re going to wait and see what other countries are going to do in supporting Saudi,” the official said, reiterating Defense Secretary Mark Esper’s comments in a Pentagon briefing Friday.

Esper spoke with his counterparts in the United Kingdom, France and Germany over the weekend, the official said.

“They all came out today and indicated that they also believe that Iran is responsible," the official added.

Esper told reporters Friday that, without any solid plans laid down, the troops would be primarily from an air and missile defense background.

“They’ve got to go through the process of talking to the combatant commands to see who can contribute,” the official said Tuesday.

The deployment would be the hundreds, rather than thousands, Marine Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, told reporters Friday.

That number is still under discussion, the official said Tuesday.

“The European announcement and the possibility they may send forces could change U.S. contribution,” he said.