United Nations

• Video report by ITV News reporter Olivia Kinsley

The Syrian government has been blamed for a third toxic gas attack, according to a confidential report to the UN Security Council.

The fourth report from a 13-month-long inquiry by the UN and the Organization for the Prohibition of Chemical Weapons blamed government forces for an attack in Qmenas on March 16 last year.

A report in August blamed the Syrian government for two chlorine attacks in 2014 and 2015 and said so-called Islamic State had used sulfur mustard gas.

The new report sets up a potential showdown between Russia and western Security Council members over how to respond.

It said Syrian government forces had used helicopters to drop barrel bombs, which then released chlorine gas. However, it "could not confirm the names of the individuals who had command and control of the helicopter squadrons at the time".

President Obama has said "many" wealthy nations are not doing enough to help refugees.

Speaking at the UN General Assembly for the last time, he said: "We should all understand that ultimately our world would be more secure if we are prepared to help those in need and the nations who are carrying the largest burden with respect to accommodating these refugees.

"There are a lot of nations right now that are doing the right thing. But many nations, particularly those blessed with wealth and the benefits of geography that can do more to offer a hand, even if they also insist that refugees who come to our countries have to do more to adapt to the customs and conventions of the communities that are now providing them a home."

President Obama has hailed the progress the United Nations has made over the last eight years, as he spoke at the General Assembly in New York for the last time.

He said the UN had "returned the global economy to growth" from the "depths of the greatest financial crisis of our time".

Mr Obama also praised the UN's work in resolving the Iran nuclear issue through diplomacy, opening relations with Cuba and helping Colombia end "Latin America's longest war".

The UN's assistance has helped people "feed themselves", he said, and "power communities across Africa" while promoting "models of development rather than dependence."

The outgoing US President also hailed the UN's work in making international institutions such as the world bank and International Monetary Fund "more representative", while "establishing a framework to protect our planet from the ravages of climate change".