Pressure is being exerted from all directions, officials acknowledge, with Washington's concern over a pre-emptive Israeli strike reflected in the steady stream of senior officials arriving in Jerusalem for top-level talks.

The latest visitor was US National Security Adviser Tom Donilon, who yesterday held a two-hour meeting with Prime Minister Benjamin Netanyahu, and held similar in-depth talks with Defence Minister Ehud Barak, whose "hawkish line" on Iran is worrying Washington, Haaretz newspaper reported today.

Later this week, US intelligence chief James Clapper is also due to arrive, press reports said.

Barak, Netanyahu's de facto deputy, has been "summoned" to Washington next week, media reports said, ahead of a visit by the premier himself in early March.

"Israel is under pressure from all sides. The Americans don't want to be surprised and faced with a fait accompli of an Israeli attack," a senior Israeli official told AFP, speaking on condition of anonymity.

"They are telling us to be patient and see if the international sanctions against Tehran will eventually work," he said.

In an interview with CNN this weekend, top US military commander Martin Dempsey gave a blunt assessment that it would be "premature" to launch military action against Iran.

For several weeks, Israel has blown hot and cold over the possibility of a pre-emptive military strike on Iran's nuclear facilities, which much of the West believes masks a weapons drive.

"For now, we are trying to nurture a certain vagueness, partly to push the international community to impose even tougher sanctions against Iran," he said.

"But at the same time, we are dealing with the usual polyphony from Israel's political class," he acknowledged.

The United States is not alone in wanting to curb the warlike tendencies apparent in some Israeli circles.

Yesterday, Britain's Foreign Secretary William Hague said it would not be "wise" for Israel to take military action against Iran, echoing comments earlier this month by French President Nicolas Sarkozy.

"The solution is never military, the solution is political, the solution is diplomatic, the solution lies in sanctions," he told French Jewish leaders on February 8.