US President George W. Bush's administration said there is no trade-off in its plans to sell billions in sophisticated weaponry to oil-rich Persian Gulf states whose cooperation Washington is courting in Iraq. "There isn't an issue of quid pro quo," US Secretary of State Condoleezza Rice said of the proposed sales to Saudi Arabia and other nations that have until recently committed little other than rhetoric to the US-backed democratic experiment in Iraq. The sales, along with an aid package for Israel and Egypt announced Monday, are the fruit of years of partnership and recognition of the region's strategic importance, Rice said. Although she did not mention oil, that is the region's chief export and the origin of the historic US alliance with Saudi Arabia. "We have the same goals in this region concerning security and stability," and many of the same concerns about the progress of political unification in Iraq, Rice told reporters as she left for a lobbying tour of the region with Defense Secretary Robert Gates. The administration announced the proposed US arms package, estimated at more than $20 billion (â‚¬14.64 billion), the morning that Bush's two top national security aides left for meetings with Saudi King Abdullah and other leaders. The administration framed the weapons sales, which must be approved by Congress, as a way to strengthen relatively moderate regimes against extremist regimes and ideologies. An increasingly ambitious Iran is the chief opponent. "There isn't a doubt, I think, that Iran constitutes the single most important, single-country challenge to ... US interests in the Middle East and to the kind of Middle East that we want to see," Rice said. The meeting Tuesday, at the Red Sea resort of Sharm el-Sheik, is the first time Gates and Rice have joined for a diplomatic visit, suggesting an almost last-ditch effort to get Iraq's Arab neighbors to fulfill their promises to help stabilize the war-ravaged country. Gates and Rice have little more than a month to cobble together the diplomatic and military progress needed to show Congress that Bush's latest strategy in Iraq is working and deserves more time.