"The idea here is to help Israel create a layered missile defense capability to protect it from all sorts of threats in the region, near and far," said the official, who spoke on condition of anonymity.
Gates discussed the Israeli request Monday in a meeting with Israeli Defense Minister Ehud Barak, the official said.
Besides the radar, Gates also agreed to explore sharing missile early warning launch data, as well as US funding for two costly Israeli projects designed to counter short-range rockets and mortars, he said.
The official said deploying the X-band radar was a near-term proposition, adding "all this is moving pretty quickly."
"We are going to station this land-based system there, and the Israelis would plug into it," said the official.
An X-band radar is a powerful phased array radar that can target the warhead of a long or medium range missile in space. The United States has deployed one in Japan and plans to install a larger X-band radar in the Czech Republic.
The official linked the assistance to the US administration's push for progress on a roadmap for peace between Israel and the Palestinians.
But it appeared to be more directly related to Israel's concern about Iran's nuclear program.
"A policy that consists of keeping all options on the table must be maintained," Barak told Gates, according to the Israeli defense ministry.
"Iran's plans pose a threat to regional and global stability. We insist that it is vital to continue tightening the economic and financial sanctions imposed on the Iranians," he said.
Pentagon press secretary Geoff Morrell reaffirmed US preference for a strategy that combines economic and political pressure on Tehran to give up its uranium enrichment program.
"I think the Israelis are keenly aware that we believe the best possible avenue of dissuading the Iranians from pursuing nuclear weapons is through economic and political pressures," Morrell said.
"We certainly understand that the Israelis view a nuclear Iran as an existential threat -- they have made that abundantly clear to us, to the world. And we are working diligently to prevent that from happening," he said.
"But the way we are focusing our efforts is on diplomatic, economic, financial pressures," he said.
Morrell added that "a military option is always available to us. It's not our first choice."
Despite the difference in emphasis, Morrell said the two sides had a "shared strategic vision and a common understanding of the threats to the Middle East and emanating from it."
Gates assured Barak that they would explore providing Israel with additional defensive capabilities, Morrell said. But the press secretary would not say what they were.
An Israeli statement said Gates had promised to explore providing a forward deployed missile defense radar, missile early warning launch data, and counter-measures against short-range rockets and mortars.
© 2008 Agence France Presse