Israel asks US not to soften on Iran

Israel's message has been subtle, to ensure it is not seen as pushing America to war. Officials stressed support for diplomacy as the main avenue to pursue at present, but underlined the need "to prepare for all other options" as chief of staff Gabi Ashkenazi said after meeting with his Pentagon counterparts last week.

"Every day that passes, Iran moves closer to achieving nuclear ability and every day sanctions get closer to stopping Iran getting there. The question is, what will happen first," said an Israeli official.

The administration insists that its policy is unchanged, and both presidential candidates, Republican John McCain and Democrat Barack Obama, support leaving the military option open.

The US is also seeking to ease Israeli concerns by upgrading Israel's early warning systems to protect it from a possible Iranian missile attack. Mr Gates promised Mr Barak that the US would supply Israel with an advance X-band radar system, which can provide information on high altitude long-range missiles.

America, Mr Gates said, would also share real time data from its spy satellites which can detect a missile launch from any point on the globe within seconds.

"These agreements will increase Israel's safety and its ability to defend itself from an attack," Mr Barak said after his meetings in Washington.