The European Union has agreed to impose fresh sanctions on Iran following a report by the UN's atomic agency that said Tehran was planning to build nuclear weapons.
Sanctions have also been extended to Syria, following 10 months of a brutal crackdown against pro-democracy protesters, in which more than 3,500 people have been killed.
Following a meeting of in Brussels on Thursday, ministers agreed to place sanctions on 39 individuals and 141 businesses, including the freezing of assets and travel bans.
In a statement released after the meeting, the sanctions on Iran were said to be aimed at "severely affecting the Iranian financial system, in the transport sector, in the energy sector".
Before the meeting, William Hague had called for an increased "isolation" of the Iranian regime after the storming of the British embassy in Tehran on Sunday.
A week before, the British Foreign Office imposed its own sanctions on all Iranian banks, leading to chants of "death to Britain" in the Iranian parliament.
However, the EU said the new sanctions had no connection with the breach in the Vienna Convention, covering the security of diplomats and foreign property.
Subsequent to the ransacking of the embassy, the British government withdrew its diplomats and consulate staff. France, Germany, Netherlands and Italy have since done likewise.
In a statement, EU ministers said: "The council agreed to broaden existing sanctions by examining, in close co-ordination with international partners, additional measures including measures aimed at severely affecting the Iranian financial system, in the transport sector, in the energy sector."
The sanctions will not include the banning or Iranian oil, though minister did leave the door open for a new round of sanctions in January.
Speaking to BBC Radio 4's Today programme, Hague said: "Our long-term concern is, of course, the nuclear programme, the danger that poses to the peace of the Middle East and the wider world, the threat of proliferation spreading to other countries in the region."
After the meeting, Hague welcomed the further package of EU sanctions
"This tenth round of sanctions aims to increase pressure on the Syrian regime to stop the continuing violent repression of the Syrian people. EU sanctions stand alongside measures introduced by Turkey yesterday including the freezing of assets belonging to Assad and individuals in the regime, and the Arab League’s decision to impose unprecedented sanctions. I welcome these moves which send a clear message that the Syrian regime’s actions have left it isolated.
“EU sanctions are part of a broad international response to the horrific abuses perpetrated by a regime that has lost legitimacy. The UN Human Rights Council’s Commission of Inquiry report, issued on 21 November, highlighted the systematic and wide ranging nature of these abuses including through compelling testimony from many of those who have suffered at the hands of the Syrian regime. The UK worked closely with international and regional partners to secure a third UN Human Rights Council special session on Syria, on Friday 2 December."
The foreign secretary also added his support the Arab League’s efforts to end to the violence in Syria.