Israeli Prime Minister Benjamin Netanyahu urged world powers on Sunday to set a "clearred line" for Tehran's atomic activities and said they had failed to convince it of their resolve to prevent Iran from obtaining nuclear arms.

Israeli Prime Minister Benjamin Netanyahu urged world powers on Sunday to set a "clearred line" for Tehran's atomic activities and said they had failed to convince it of their resolve to prevent Iran from obtaining nuclear arms.

Netanyahu's remarks suggested a growing Israeli impatience with its main ally, the United States, and other countries that have been pressing him to give diplomacy and sanctions more time to work and hold off on any go-it-alone Israeli strike on Iran.

"I believe the truth must be stated: The international community is not placing a clear red line for Iran and Iran does not see international resolve to stop its nuclear programme," Netanyahu told his Cabinet.

"Unless Iran sees this clear red line and this clear resolve it will not stop moving forward with its nuclear programme, and Iran must not have nuclear weapons," he said in broadcast remarks.

Although Netanyahu did not single out the United States or US President Barack Obama in his criticism, Israeli officials have said they hope for stronger language from the president about possible US military action.

Obama, who has had a frosty relationship with Netanyahu, has insisted he will not allow Iran to build atomic weapons and that all options are on the table.

On Saturday Tzachi Hanegbi, an influential former Israeli legislator and a Netanyahu confidant, said "the rhetoric of the US President is too vague, very amorphous" and Iran was not taking Obama's words seriously.

In a US election year, Republican candidate Mitt Romney has also sharply criticised Obama's handling of Iran as not being tough enough.

Tehran says it is refining uranium to fuel a planned network of nuclear power plants so that it can export more of its oil and gas. The United States and its allies accuse Iran of a covert bid to develop the capability to make nuclear bombs.

Israel, believed to have the only nuclear arsenal in West Asia, views a nuclear-armed Iran as a threat to its existence.

UN Address
Netanyahu has said he will speak out about the dangers of Iran in an address this month to the UN General Assembly in New York. He is also expected to hold talks with Obama during his visit, but no announcement has yet been made.

A senior Israeli official told Reuters last week Netanyahu would seek a firm pledge of US military action if Iran did not back down on uranium enrichment. Such a promise could dissuade Israel from attacking Iran alone, Israeli officials have said.

A United Nations report said on Thursday that Iran had more than doubled the number of centrifuges in its fortified bunker at Fordow since May, showing it was still expanding its nuclear programme despite Western pressure and threat of Israeli attack. The new machines are not yet operating, the report said.

"The report confirms what I have been saying for a longtime, international sanctions are a burden on Iran's economy but they are not in any way delaying the advancement of Iran's nuclear programme," Netanyahu told his Cabinet, in public remarks opening the meeting.