UNITED NATIONS: Western nations on Thursday accused Iran of carrying out “alarming” breaches of UN nuclear sanctions, often with Syria's aid.

The United States, France and Britain also stepped up demands for the publication of a UN Security Council expert report on Iran sanctions which are being blocked by Russia.

The experts' report contains “troubling findings” about sanctions violations, said US ambassador to the United Nations Susan Rice.

The experts set out a “complete and alarming” picture of Iran's violations, said French deputy UN ambassador Martin Briens, who highlighted three new cases of trading in arms and related technology reported since March.

No details of the case were made public at Thursday's Security Council meeting on the Iran sanctions regime.

Four rounds of UN sanctions have been ordered against Iran over its refusal to halt uranium enrichment. Western nations accuse Iran of seeking a nuclear bomb, while Tehran insists its nuclear drive is for civilian energy.

Stepping up pressure on Iran in recent months, Israel says it has intercepted a shipload of Iranian arms being transferred through Syria to the Gaza Strip. Iran has also been accused of providing missiles to the Taliban militia in Afghanistan. It denied the charge.

Iran's breaches involve nuclear and ballistic weapons and all other categories of sanctions passed, Briens told the meeting.

“They involve increasingly complex methods: the use of front companies, assumed names, using multiple financial intermediaries and currency exchange offices, physically hiding things, false statements and forgery,” the French envoy said.

Syria is implicated in nearly all the violations and is itself refusing to cooperate with the panel of experts, Briens said. According to a copy of the blocked report seen by AFP, six of the nine arms transfer violations reported involved Syria.

The report also says that Iran's Revolutionary Guard and state shipping line, IRISL, are increasingly involved in sanctions violations. It says dozens of the maritime company's ships have had their names changed in recent months.

The US ambassador said the international community “must further strengthen the implementation and enforcement of UN sanctions.” Rice backed the speedy implementation of recommendations made by the experts to tighten enforcement.

“It is clear that Iran continues to proliferate and continues to pursue a nuclear weapons program. Iran has given us no good reason to believe that it is willing to engage in meaningful negotiations on its nuclear program,” said Britain's UN ambassador Mark Lyall Grant.

Lyall Grant, along with the French and US envoys, demanded the Iran sanctions report be urgently made public. Russia has led a block on the release of the report, calling the document “sloppy”.

Russia's deputy UN ambassador, Alexander Pankin, did not mention the block but told the Security Council meeting: “Unverified and politicized information would not help” the council.