The unanimous adoption of a United Nations Security Council resolution designed to choke off funding and recruits for Islamic State (IS) and other terrorist groups sends a "clear political message" that the world will act to tackle the threat, the UK's ambassador said.
Sanctions including a travel ban are being imposed on six prominent figures including the IS spokesman and the resolution warns action will also be taken against others held responsible for financing or recruiting foreign fighters.
The vote came after European Union (EU) foreign ministers approved the arming by member states of Kurdish troops trying to resist the extremists' push to expand their sphere of control in Iraq.
Foreign Secretary Philip Hammond said Britain - which has been transporting weapons provided by other countries - stood ready to "consider favourably" any request by Kurdish leaders for it to join the US and France by directly supplying military equipment.
But the chairman of the Commons defence committee Rory Stewart - a former deputy governor of an Iraqi province - warned a long-term strategy was needed and that Britain lacked adequate information about the situation.
Sir Mark Lyall Grant, the UK's UN ambassador, said the resolution represented a "comprehensive rejection" of IS.
But he said it was only a first step and urged the international community to be " resolved, active and creative in considering what further measures should be taken to tackle this terrorist scourge".
"The council has taken a firm and united response," he said at the session of the Security Council, which is chaired by the UK at present.
"This resolution provides an additional framework for a longer-term and strategic international response to the threat.
"In particular, it sends a clear political message that the international community utterly condemns Isil's brutal and mindless terrorist acts, rejects its extremist terrorist ideology and is united in its resolve to oppose and confront it.
"It contains measures to choke off recruitment and target the growing phenomenon of foreign terrorist fighters.
"It tackles the financing of terrorism, calling on all member states to cease immediately all trade and material support that enables Isil and other terrorist groups to function."
The blacklisting of six figures and threats of further sanctions "sends a clear signal that there is no impunity for those who seek to support al Qaida or its splinter groups," he said.
Kurdish Peshmerga fighters have been at the forefront of efforts to halt the IS advance and their efforts have been praised for helping thousands of Yazidis flee from Mount Sinjar, where they had been trapped by the jihadists.
But they have complained about being outgunned by IS, leading to the offers of support from western governments.
Mr Hammond said IS represented a threat to civilisation and promised support for any inclusive new administration in Baghdad following the replacement as Iraqi prime minister of Nouri Maliki, who is accused by critics of fuelling sectarianism, helping the rise of IS.
There have been signals from political leaders from the Sunni majority that they could join a government led by new premier Haider al-Abadi.
In a statement issued after the meeting, the EU said it "welcomes the decision by individual member states to respond positively to the call by the Kurdish regional authorities to provide urgently military material", but that it was up to individual member states how to act.
It is also to examine ways to prevent the extremists benefiting from oil revenues.
There was an "international and European responsibility to co-operate with Iraq in our common fight against terrorism", the statement said.
Downing Street said two planeloads of UK aid were en route to the Kurdish capital Erbil, from where they will be sent to the Dahuk region, which has seen its population swell by 50% with the arrival of 450,000 refugees.
The supplies include cooking equipment to be distributed by the World Food Programme and the UK is also working with UN agencies to accelerate the distribution of financial aid to the non-governmental organisations (NGOs) working on the ground.
A UK-drafted United Nations Security Council resolution seeking to stem the flow of finance to IS and sanction those who are seeking to recruit jihadists is due to be voted on in New York this evening.
Tory MP Mr Stewart, who is visiting Kurdistan, said the present violence "feels like the beginnings of a civil war".
"We need far more information; I don't personally feel we have enough diplomats on the ground who really understand who Isis are and what's going on," he told Channel 4 News.
"But we also need to accept that in the end Isis are a seriously bad force and anything that we can do to protect populations and contain their expansion we ought to."
He said, however, that he believed it would be "very difficult" to secure public and parliamentary support for UK air strikes after the experience of the aftermath of the 2003 invasion.