Her meetings in Beijing on Monday and Tuesday will outline potential further UN sanctions which could be taken against Tehran if it fails to halt uranium enrichment, which the West fears is a cover for atomic weapons development.

Iran strongly denies claims it is attempting to develop nuclear arms.

Livni's visit follows trips by Israeli Prime Minister Ehud Olmert to Russia, France and Britain in a bid to agree a sanctions strategy. Olmert also visited Beijing in January for discussions on Iran's nuclear policy.

Earlier this week the United States announced that the six major powers involved in sanctions planning against Iran -- America, Russia, China, Britain, France and Germany -- would meet in Europe in early November to discuss tightening sanctions.

Foreign ministers from the six decided in September to convene a meeting but agreed to wait until November, when new information about Iran's nuclear programme should become available.

Washington announced unilateral sanctions against three banks and several units of the Iranian military on Thursday, but Iran's new chief nuclear negotiator Saeed Jalili denied they would effect nuclear policy.

Israel has previously described Iran as its principal strategic threat, and earlier this month US President George W. Bush warned of a possible World War III if Tehran acquired nuclear weapons.

American Vice President Dick Cheney has also warned of "serious consequences" for Iran if it continues to defy global demands that it freeze sensitive nuclear work.

The latest US sanctions targeted the Islamic Revolutionary Guard Corps, accused of spreading weapons of mass destruction (WMD), and the IRGC's elite Quds Force, which was branded a supporter of terrorism.

Three Iranian state-owned banks were also blacklisted, along with IRGC-controlled companies and the logistics arm of Iran's defence ministry, as Washington stepped up a drive to squeeze Iran out of global banking.