Barack Obama: IS "must be degraded and then ultimately destroyed"
The UN Security Council has adopted a binding resolution compelling states to prevent their nationals joining jihadists in Iraq and Syria.
US President Barack Obama chaired the session and said nations must prevent the recruitment and financing of foreign fighters.
US and Arab jets bombed Islamic State (IS) targets in Syria for a second day, including oil facilities, the US says.
Mr Obama urged global efforts to dismantle the IS "network of death".
The US-drafted resolution was adopted unanimously.
The US launched air raids against IS militants in Iraq last month and on Monday night expanded the strikes into Syria, with the participation of Gulf Arab allies.
IS now controls several oilfields in Syria and Iraq, and sales of smuggled crude oil have helped finance its offensive in both countries.Call to action
UK Prime Minister David Cameron said nations must deal with all forms of extremism, including banning "preachers of hate" and fighting "poisonous ideology".
He told the UN council session that the Iraq and Syria conflicts were attracting young recruits from prosperous countries.
Mr Obama said "the words spoken here today must be matched and translated into action... within nations and between them, not just in the days ahead but for years to come".
In his earlier speech to the UN General Assembly he condemned IS, saying "there can be no reasoning - no negotiation - with this brand of evil".
More than 40 countries had offered to join the anti-IS coalition, he said.
IS aims to set up a hardline caliphate. The well-armed Sunni Muslim militants have seized a huge swathe of Syria and Iraq, forcing whole communities to flee in terror. They have beheaded Western hostages and have persecuted Christians, Yazidis and Shia Muslims, whom they treat as heretics.Multiple air strikes
In the past 24 hours US warplanes hit IS vehicles and arms dumps near Abu Kamal on the Syria-Iraq border and Deir al-Zour in the east of Syria. In Iraq there were strikes west of Baghdad and southeast of Irbil, near Kurdish territory, the US military said.
Earlier there were air strikes on IS near the border with Turkey.
Meanwhile an Algerian jihadist group linked to IS - Jund al-Khilafa - has released a video which it says shows militants beheading a French tourist. Herve Gourdel was kidnapped on Sunday in Algeria's troubled Kabylie area.Analysis - Nick Bryant, BBC News, New York
When President Obama addressed the UN General Assembly 12 months ago, he spoke of Iraq mainly in the context of America's withdrawal - a country in his rear-view mirror.
Yet the fight in Iraq and Syria against Islamic State, a militant group he once likened, derisively, to a junior basketball team, could dominate his remaining years in office.
America would not base its entire foreign policy on reacting to terrorism, he stressed, but it is certain to take up much of the remaining bandwidth.
The phrase that will linger is "the network of death," but Obama was at pains to point out this is no clash of civilisations. Nor is America acting alone. Over 50 nations will contribute to the fight against Islamic State.
That fight, he said, needed to be ideological as well as military. He called for a new compact among civilised peoples to "eradicate war at its most fundamental source - the corruption of young minds by violent ideology."
"The only language understood by killers like this is the language of force," Mr Obama told the UN General Assembly.
The US "will work with a broad coalition to dismantle this network of death," he said.
"In this effort, we do not act alone. Nor do we intend to send US troops to occupy foreign lands. Instead, we will support Iraqis and Syrians fighting to reclaim their communities. We will use our military might in a campaign of air strikes to roll back Isil [IS].
"We will train and equip forces fighting against these terrorists on the ground. We will work to cut off their financing, and to stop the flow of fighters into and out of the region... Today, I ask the world to join in this effort," he said.
He urged Muslims to reject the ideology of IS and al-Qaeda.
The IS advance has created a refugee crisis in Turkey. Aid agencies said some 130,000 Kurdish refugees, most of them from Kobane, crossed into Turkey at the weekend.
The US has launched nearly 200 air strikes against IS in Iraq since August.
The US said Saudi Arabia, the United Arab Emirates, Jordan, Bahrain and Qatar had all "participated in or supported" the strikes on IS in Syria this week.
''I'm grateful... to America and her partners,'' one refugee told the BBC
The strikes on Tuesday also targeted Khorasan, a shadowy group of al-Qaeda fighters in Syria's Aleppo province. The US military says it is investigating whether the attack killed Khorasan's leader Mohsin al-Fadhli.
The Dutch government says it will deploy six F-16 fighter jets to join the US-led air campaign. The Netherlands will also send about 130 military trainers to Iraq.
Meanwhile, the UK Parliament will be recalled on Friday to discuss Britain's possible role in air strikes on IS targets.
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