PRINCE SULTAN AIR BASE, Saudi Arabia — Defense Secretary Mark Esper says he will urge allies later this week to contribute more to the defense of Saudi Arabia and the Gulf region to counter threats from Iran.

The plan is part of a broader U.S. effort to get NATO allies to take on more responsibility for Gulf security. That has included U.S. pleas for nations to send ships, aircraft and air defense systems to the region.

The U.S. has already agreed to send three Patriot missile batteries, dozens of fighter jets and other aircraft to Saudi Arabia. Esper got a look at one of the Patriot batteries Tuesday as he toured a military base there.

He says the Saudis will “help underwrite” some of the U.S. costs for the additional aid, which includes about 3,000 American troops.