Iran has been subjected to four rounds of United Nations Security Council sanctions in relation to its nuclear programme.
In spite of this, it has continued its uranium enrichment operations and there is growing pressure for sanctions to be tightened further.
The following are the UN resolutions relating to Iran's nuclear programme.
DEMAND TO END ENRICHMENT - RESOLUTION 1696
In March 2006, the issue was discussed at the UN Security Council, which called for a report by the IAEA to establish Iran's compliance with the terms of the nuclear non-proliferation treaty (NPT).
The treaty allows for the use of nuclear technology for peaceful energy purposes, as long as countries can demonstrate that their programmes are not being used for the development of nuclear weapons.
In July 2006, the Security Council said it was "seriously concerned" that the IAEA was unable to provide assurances about Iran's undeclared nuclear material. It demanded that Iran "suspend all enrichment-related and reprocessing activities, including research and development", giving it one month to do so. Failing that, it would face the possibility of economic and diplomatic sanctions.
Iran asserted that its nuclear programme was for civilian use permitted by the NPT. On this basis it said it rejected the validity of the Security Council's calls. It claimed that while subscribers to the NPT were being punished, those who had not signed up to the agreement were being rewarded by generous nuclear cooperation agreements.
FIRST ROUND OF SANCTIONS - RESOLUTION 1737
The deadline for Iranian compliance with the Security Council's demands passed without being heeded. In December 2006, the Council unanimously adopted Resolution 1737.
This called on states to block Iran's import and export of "sensitive nuclear material and equipment" and to freeze the financial assets of those involved in Iran's nuclear activities.
The Council decided that all countries should prevent the supply or sale of equipment and technology that would aid Iran's nuclear programme in any way.
SECOND AND THIRD ROUNDS OF SANCTIONS - RESOLUTIONS 1747 AND 1803
With Iran's nuclear programme ongoing, in March 2007 the Security Council voted to toughen sanctions. It banned all of Iran's arms exports. It also froze the assets and restricted the travel of people it deemed involved in the nuclear programme.
Financial and trade
Further restrictions imposed in March 2008 encouraged scrutiny of the dealings of Iranian banks.
It also called upon countries to inspect cargo planes and ships entering or leaving Iran if there were "reasonable grounds" to believe they were goods prohibited by previous resolutions.
FOURTH ROUND OF SANCTIONS - RESOLUTION 1929
In June 2010, the Council approved fresh sanctions against Tehran.
The measures prohibit Iran from buying heavy weapons such as attack helicopters and missiles.
They also toughen rules on financial transactions with Iranian banks and increase the number of Iranian individuals and companies that are targeted with asset freezes and travel bans.
There is also a new framework of cargo inspections to detect and stop Iran's acquisition of illicit materials.
The sanctions were passed after being watered down during negotiations with Russia and China. There are no crippling economic sanctions and there is no oil embargo.