RIYADH, Saudi Arabia (AP) - U.S. Defense Secretary Robert Gates was keeping up the pressure on Iran on Wednesday, consulting with the United States' closest and most influential ally in the Persian Gulf about how to respond to Iran's disputed nuclear program.
U.S. officials said Gates would discuss shared concerns over Iran's nuclear intentions and ballistic missile program during meetings with Saudi King Abdullah and senior leaders.
Gates arrived in the Saudi capital after three days in Afghanistan. He nearly crossed paths with Iranian President Mahmoud Ahmadinejad, who was in Kabul on Wednesday for meetings with many of the same leaders Gates had just seen.
Gates accused Iran of "playing a double game" in Afghanistan, and working to undermine the security U.S. forces are trying to help build.
Afghanistan is just one of the places where the United States has a proxy fight with Iran, and the confrontation appears to be getting nastier. The Obama administration has all but written off hopes for a diplomatic opening with Iran after three decades of enmity.
Last week, the top American commander in the Middle East, Gen. David Petraeus, said Iran had gone from being a "theocracy to a thugocracy" in its crackdown on a reform movement following last year's elections.
The predominantly Sunni Arab Middle East - and Gulf nations in particular - have been wary of the growing influence of Shiite Iran, and Saudi Arabia has long warned of the potential for a nuclear arms race in the Gulf region if Iran gained the bomb. Saudi Arabia and other Sunni states see Iran's expanding missile capability as an even more immediate threat.
The U.S. military is trying to reassure Gulf allies by buttressing its defense systems with upgraded Patriot missiles on land and more U.S. Navy ships capable of destroying missiles in flight.
The Patriot missile systems, which originally were deployed in the region to shoot down aircraft, have now been upgraded to hit missiles in flight.
Petraeus revealed in January that the U.S. now has eight Patriot missile batteries stationed in the Gulf region - two each in four countries. He did not name the countries, but a military official told The Associated Press that they are Kuwait, the United Arab Emirates, Bahrain and Qatar. The official spoke on condition of anonymity because some aspects of the defensive strategy are classified.
Iran has missiles with ranges of more than 1,250 miles, capable of striking Israel or U.S. bases in the region. Iranian missiles could also hit near neighbors such as Saudi Arabia, although Iran denies any such intent.
The United States and its Western allies have been pushing for a fourth round of U.N. sanctions against Iran over its nuclear program, especially because it refuses to freeze its uranium enrichment program and due to belated revelations that it was building a secret, fortified plant.
But Russia and China are skeptical about any new U.N. penalties. Recent meetings have not resulted in any agreements on sanctions.
China, which has extensive trade ties with oil giant Iran, traditionally opposes sanctions but went along with three earlier rounds of limited sanctions.
On Tuesday, Iran urged China to resist pressure to vote for sanctions.