Israel presented its list of desired military hardware and other backup for the strike during President George Bush's visit to Jerusalem in May, the Israeli newspaper, Ha'aretz, said.
This was turned down with Washington officials insisting Israel give the US prior notice if it plans an attack.
The US is among a group of nations which has sought to engage with Iran over its nuclear activities by offering a package of incentives if Tehran suspends uranium enrichment.
Iran insists it is interested only in civil nuclear power but the US and EU claims it plans to build a nuclear bomb.
Israel, which has its own undeclared nuclear arsenal, has warned Iran repeatedly against developing its own. A major Israeli air force exercise in June was viewed by observers as a veiled warning to Iran that Israel has the capability to attack the country's nuclear facilities.
According to Ha'aretz, Bush held talks with the country's prime minister, Ehud Olmert, and defence minister, Ehud Barak, during which they requested "certain specific items of military equipment" as well as diplomatic backing.
The paper - which does not specify the hardware sought - says that the US took this to imply an attack on Iran was imminent and sent a "strong message" to Israel not to do so.
It also demanded prior warning of any attack, and offered in compensation to improve Israel's missile defence systems.
Israel rejected this and warned it "reserves the right to take whatever action it deems necessary" if diplomatic efforts achieved nothing.
Ha'aretz says Israel had hoped Bush would order an American strike before leaving office but that this was seen as unlikely. The country fears that an Israeli attack "would give Iran international legitimacy for its programme, which it currently lacks" and portray Israel as the aggressor.
Israel believes that Iran will continue to stall, perhaps even temporarily suspending uranium enrichment, "in an effort to see out the rest of Bush's term in peace", the paper added.
© 2008 The Guardian