(Adds Pentagon comments, details on deployment, possible next steps)
By Phil Stewart and Idrees Ali
WASHINGTON, Sept 26 (Reuters) - The Pentagon said on Thursday it plans to send four radar systems, a battery of Patriot missiles and about 200 support personnel to bolster Saudi Arabia's defenses after the largest-ever attack on the kingdom's oil facilities this month.
The Pentagon's statement added details to the Pentagon's announcement on Friday about U.S. plans to deploy more forces to Saudi Arabia after the Sept. 14 attack on the world's biggest crude oil-processing facility, which Washington has blamed on Iran.
Still, the deployment is more limited than U.S. officials previously told Reuters was under consideration by the Trump administration following the attack on Saudi Arabia.
Reuters previously reported the Pentagon was considering keeping an aircraft carrier in the Gulf region indefinitely, as speculation mounts that the USS Abraham Lincoln carrier strike group will soon need to wind up its deployment.
The Pentagon left open the possibility of further announcements in the days ahead.
In a statement, the U.S. military said it was putting additional capabilities on "prepare to deploy orders," meaning they could be mobilized more quickly in a crisis. Those include two additional Patriot missile batteries, made by Raytheon Co and the Lockheed Martin Corp-built, Terminal High Altitude Area Defense system, or THAAD.
The U.S. military deployments appear to close the door to any near-term decision to wage retaliatory strikes against Iran following the attack, which rattled global markets and exposed major gaps in Saudi Arabia's air defenses.
U.S. President Donald Trump said on Friday that he believed his military restraint so far showed "strength," as he instead imposed another round of economic sanctions on Tehran.
Iran denies any involvement and the Iran-aligned Houthi rebels in Yemen have claimed responsibility for the attack.
Washington says the trajectory of the incoming missiles and drones eliminate Yemen, however, as the staging ground for the strike.
Saudi Arabia's top diplomat, Adel al-Jubeir, said this week the United Nations was helping it identify the launch site, but suggested the investigation could take weeks, not days, to complete.
France has also sent a team of military experts to investigate, including specialists in explosives, missile trajectory and ground-to-air defense systems.
The United States has been trying to rally the international community toward joint action to deter additional attacks by Iran or Iran's proxies. This week, Britain, France and Germany said in a joint statement it was clear Iran was responsible for the attack, adding: "There is no other plausible explanation."
Pentagon spokesman Jonathan Hoffman, without naming any individual nations, suggested that Washington expected other allies to contribute more militarily.
"Other countries have called out Iranian misadventures in the region, and we look for them to contribute assets in an international effort to reinforce Saudi Arabia’s defense," Hoffman said in the statement. (Reporting by Phil Stewart and Idrees Ali; Editing by Chizu Nomiyama and Peter Cooney)