An embassy spokesman, Larry Schwartz, said they had received a "direct and credible" threat by telephone on Wednesday night. The US ambassador to Israel, Ned Walker, responded by instructing his staff to stay at home for the day.
Mr Walker, a career diplomat, took up his post a year ago. He is a Middle East specialist who served previously as ambassador to Egypt. He was in Abu Dhabi during the 1991 Gulf War.
Callers at the embassy on Hayarkon Street, a grim concrete fortress of a building overlooking the Tel Aviv beach, were advised that it would reopen next week.
Mr Schwartz described the closure as a "normal and practical step" of the kind adopted after the bombing of US embassies in Nairobi, the Kenyan capital, and in Dar-es-Salaam, Tanzania, on 7 August.
The threat was taken particularly seriously because of what he termed "the general rise in regional tensions in the past month or so", a reference to the confrontation between the US and Britain with the Iraqi leader Saddam Hussein.
The spokesman denied an Israeli radio report that the caller had threatened to assassinate the ambassador or members of his staff.
Israeli police were on duty as usual, but a spokeswoman said they had not been reinforced. Hayarkon Street, a narrow, congested road, remained open to traffic but police sappers were checking vehicles in the embassy car park.
As of last night, Israeli police were not involved in hunting the would- be bombers. The only assistance requested by the Americans was to try to trace the threatening phone call. The CIA, through its station chief in Tel Aviv, has close working links with the Palestinian and Israeli security services.
US embassies have been on alert since the East African bombings, which killed 224 people, including 12 Americans. Washington blamed them on the fugitive Saudi Arabian millionaire, Osama bin Laden.
As tensions rose in the Gulf in early December, the State Department ordered 40 US embassies in Africa to close. Diplomats' families and non- essential embassy staff were called home from Israel and Kuwait, potential targets for retaliatory missile strikes. The US and Britain advised their citizens to stay away.
Meanwhile in Baghdad, Iraq's ambassador to the UN, Nizar Hamdoon, said Iraq will continue to attack US and British aircraft enforcing no-fly zones in the north and south of the country. In a statement broadcast on CNN, Mr Hamdoon said: "We will continue [to carry out attacks] until the US and the UK decide to pull out."In spite of the threat, US planes conducted routine patrols yesterday in the southern and northern no-fly zones.Reuse content