Foreign Secretary Philip Hammond is told the UN that Britain will continue to bomb Islamic targets for "as long as it takes" and urged leaders to unite to fight against the extremist group.
At the UN General Assembly in New York, he said leaders must work together to "crush" IS and "banish its ideology from the face of the earth".
The Foreign Secretary has defended the government's decision to add four Britons to a UN sanctions list that targets al-Qaeda and Islamic State operatives.
Speaking to ITV News, Philip Hammond said that the sanctions "sent an important message" to other potential home-grown terrorists and demonstrated that the UK had a sanctions regime.
"It will prevent others from travelling around the world," he said.
The four Britons - Omar Hussain from High Wycombe, Nasser Muthana from Cardiff, Aqsa Mahmood from Glasgow and Sally-Anne Jones from Chatham - are suspected of leading recruitment drives and plotting terror attacks against the UK and elsewhere from strongholds in Syria. They will be subject to a global asset freeze and travel ban.
Britain will continue bombing IS targets, Philip Hammond tells the UN as he urges leaders to unite to "crush" the extremist group.
It made for good headlines, but in a world where UK launches drone strikes on its citizens in Syria, are travel sanctions even a threat?
Government moves to tackle Islamic State recruitment by applying international sanctions to British citizens who joined the terror group.