Israeli Prime Minister Benjamin Netanyahu is seeking cabinet support for a military strike on Iran, the Haaretz newspaper reported on Wednesday, after days of speculation about plans for an attack.

The report, citing a senior Israeli official, said Netanyahu was working with Defence Minister Ehud Barak to win support from sceptical members of the cabinet who oppose attacking Iranian nuclear facilities.

It came after days of renewed public discussion among Israeli commentators about the possibility that the Jewish state would take unilateral military action against Iran.

Israel has also successfully tested what local media called a "ballistic missile", which a defence ministry official described to AFP as a long-scheduled "test firing of the rocket-propulsion system".

Haaretz said that Netanyahu and Barak had already scored a significant win by convincing Foreign Minister Avigdor Lieberman to throw his support behind a strike.

But the newspaper cited the senior Israeli official as saying those opposed to an attack still held "a small advantage" in the cabinet.

Media reports say there is also opposition from army and intelligence chiefs.

But such action by Israel would not be without precedent.

In June 1981, Israeli planes bombed and destroyed an uncompleted French nuclear reactor in Iraq, arguing it could have been used to make atomic weapons. The attack provoked an international outcry.

The United States, which like Israel has declined to rule out military action to prevent Iran developing a nuclear weapons capability, refused to be drawn on the Israeli media reports.

"I'm not going to respond to that kind of speculation," White House spokesman Jay Carney said.

"We remain focused on a diplomatic channel here, a diplomatic course in terms of dealing with Iran."

Iran's military chief, General Hassan Firouzabadi, warned on Wednesday that his country would "punish" any Israeli strike against it.

"We consider any threat -- even those with low probability and distant -- as a definite threat. We are on full alert," he said, Fars news agency reported.

"With the right equipment, we are ready to punish them and make them regret (committing) any mistake," he said.

On Monday, Barak was forced to deny media reports that he and Netanyahu had already decided to launch an attack against Iran over the opposition of military and intelligence chiefs.

"It doesn't take a great genius to understand that in 2011 in Israel, two people cannot decide to act by themselves," he said.

On Tuesday, Barak appeared to suggest in remarks to parliament that Israel could be forced to act alone against Iran.

"A situation could be created in the Middle East in which Israel must defend its vital interests in an independent fashion, without necessarily having to reply on other forces, regional or otherwise," he said.

Haaretz said no decision had yet been taken on any military strike, and that a November 8 report from the International Atomic Energy Agency nuclear watchdog would have a "decisive effect" on the decision-making process.

The newspaper also cited Western specialists as saying any attack on Iran during the winter would be almost impossible because of thick cloud cover.

A report from London's Guardian newspaper meanwhile suggested Britain's armed forces were looking at contingency plans in the event the US opted for military action against Iran.

Thursday's edition cited unnamed defence ministry contacts as saying they believed Washington might rush forward plans for missile strikes on Iranian facilities -- and might ask for British military help.

The Guardian's sources had also been told that the IAEA report could be a "game changer".

Israel has consistently warned all options remain on the table when it comes to Iran's nuclear programme, which the Jewish state and Western governments fear masks a drive for nuclear weapons.

Iran denies any such ambition and insists its nuclear programme is for power generation and medical purposes only.