More than five million men, women and children have now fled the Syrian civil war but the world’s will to give refugees a safe home is waning, the United Nations has warned.

World leaders pledged to resettle 10 per cent of all Syrian refugees by 2018 at a meeting Geneva in March last year, but only half of the needed places have been made available.

Donald Trump has attempted to suspend what was the world’s largest resettlement programme and border closures and restrictions are growing in Europe as more asylum seekers die attempting to reach the continent than ever before.

A record of more than 5,000 migrants drowned, suffocated or froze to death in the Mediterranean in 2016 and almost 1,000 have already died this year.

Filippo Grandi, the UN High Commissioner for Refugees, said the international community must do more to help those fleeing six years of brutal conflict in Syria.

“We still have a long road to travel in expanding resettlement and the number and range of complementary pathways available for refugees,” he said.

“To meet this challenge, we not only need additional places, but also need to accelerate the implementation of existing pledges.”

A march calling for the British Government to resettle more refugees in central London on September 17, 2016. (AFP/Getty Images)

Mr Grandi said 250,000 out of half a million places pledged exactly a year ago were available, warning that efforts needed to be dramatically “accelerated”.

He added that only the most vulnerable refugees were referred for resettlement by the UN, with the measure “giving refugees the opportunity to re-build their lives, but also enriching the communities that welcome them”.

UN member states committed to increasing efforts to find homes for refugees as part of the New York Declaration for Refugees and Migrants in September, but few new programmes have emerged.

Meanwhile, people continue to flee Syria, Afghanistan, Iraq, Yemen, Libya and other war-torn countries where conflicts look unlikely to end any time soon.

Save the Children said the international community had “utterly failed” to end the crisis.

Misty Buswell, the charity's director of advocacy for Syria, said: “More than a thousand children a day have fled their country every day for the past six years, and an entire generation is now growing up as refugees, forced from their homes and facing an uncertain future.

Former child refugee Lord Dubs says he cannot understand the Government shutting down child refugee program

“These are the children who will have to rebuild Syria once the war ends, and they urgently need our support.”

She warned that many refugee families were unable to work and living without access to healthcare and education, with 750,000 Syrian refugee children are out of school.

“Even after six years this crisis is still getting bigger every day, and these children need our help now more than ever before,” Ms Buswell said.

“Yet countries around the world are increasingly shutting their borders to children seeking refuge.”

The UN Refugee Agency (UNHCR) estimates that almost 1.2 million people will need resettlement in 2017, among whom 40 per cent are Syrians amid the biggest global crisis since the Second World War.

The agency said no specific incident caused the number of Syrian refugees to pass the 5 million mark, compared to 4.8 million a year ago, as another 6.3 million people remain internally displaced inside the country.

David Cameron pledged that the UK would resettle up to 20,000 Syrian refugees by 2020 but only 4,400 people had been granted protection by September.

Refugee crisis - in pictures Show all 27 1 /27 Refugee crisis - in pictures Refugee crisis - in pictures A child looks through the fence at the Moria detention camp for migrants and refugees at the island of Lesbos on May 24, 2016. AFP/Getty Images Refugee crisis - in pictures Ahmad Zarour, 32, from Syria, reacts after his rescue by MOAS (Migrant Offshore Aid Station) while attempting to reach the Greek island of Agathonisi, Dodecanese, southeastern Agean Sea Refugee crisis - in pictures Syrian migrants holding life vests gather onto a pebble beach in the Yesil liman district of Canakkale, northwestern Turkey, after being stopped by Turkish police in their attempt to reach the Greek island of Lesbos on 29 January 2016. Getty Images Refugee crisis - in pictures Refugees flash the 'V for victory' sign during a demonstration as they block the Greek-Macedonian border Refugee crisis - in pictures Migrants have been braving sub zero temperatures as they cross the border from Macedonia into Serbia. Refugee crisis - in pictures A sinking boat is seen behind a Turkish gendarme off the coast of Canakkale's Bademli district on January 30, 2016. At least 33 migrants drowned on January 30 when their boat sank in the Aegean Sea while trying to cross from Turkey to Greece. Getty Images Refugee crisis - in pictures A general view of a shelter for migrants inside a hangar of the former Tempelhof airport in Berlin, Germany Refugee crisis - in pictures Refugees protest behind a fence against restrictions limiting passage at the Greek-Macedonian border, near Gevgelija. Since last week, Macedonia has restricted passage to northern Europe to only Syrians, Iraqis and Afghans who are considered war refugees. All other nationalities are deemed economic migrants and told to turn back. Macedonia has finished building a fence on its frontier with Greece becoming the latest country in Europe to build a border barrier aimed at checking the flow of refugees Refugee crisis - in pictures A father and his child wait after being caught by Turkish gendarme on 27 January 2016 at Canakkale's Kucukkuyu district Refugee crisis - in pictures Migrants make hand signals as they arrive into the southern Spanish port of Malaga on 27 January, 2016 after an inflatable boat carrying 55 Africans, seven of them women and six chidren, was rescued by the Spanish coast guard off the Spanish coast. Refugee crisis - in pictures A refugee holds two children as dozens arrive on an overcrowded boat on the Greek island of Lesbos Refugee crisis - in pictures A child, covered by emergency blankets, reacts as she arrives, with other refugees and migrants, on the Greek island of Lesbos, At least five migrants including three children, died after four boats sank between Turkey and Greece, as rescue workers searched the sea for dozens more, the Greek coastguard said Refugee crisis - in pictures Migrants wait under outside the Moria registration camp on the Lesbos. Over 400,000 people have landed on Greek islands from neighbouring Turkey since the beginning of the year Refugee crisis - in pictures The bodies of Christian refugees are buried separately from Muslim refugees at the Agios Panteleimonas cemetery in Mytilene, Lesbos Refugee crisis - in pictures Macedonian police officers control a crowd of refugees as they prepare to enter a camp after crossing the Greek border into Macedonia near Gevgelija Getty Images Refugee crisis - in pictures A refugee tries to force the entry to a camp as Macedonian police officers control a crowd after crossing the Greek border into Macedonia near Gevgelija Getty Images Refugee crisis - in pictures Refugees are seen aboard a Turkish fishing boat as they arrive on the Greek island of Lesbos after crossing a part of the Aegean Sea from the Turkish coast to Lesbos Reuters Refugee crisis - in pictures An elderly woman sings a lullaby to baby on a beach after arriving with other refugees on the Greek island of Lesbos after crossing the Aegean sea from Turkey Getty Images Refugee crisis - in pictures A man collapses as refugees make land from an overloaded rubber dinghy after crossing the Aegean see from Turkey, at the island of Lesbos EPA Refugee crisis - in pictures A girl reacts as refugees arrive by boat on the Greek island of Lesbos after crossing the Aegean sea from Turkey Getty Images Refugee crisis - in pictures Refugees make a show of hands as they queue after crossing the Greek border into Macedonia near Gevgelija Getty Images Refugee crisis - in pictures People help a wheelchair user board a train with others, heading towards Serbia, at the transit camp for refugees near the southern Macedonian town of Gevgelija AP Refugee crisis - in pictures Refugees board a train, after crossing the Greek-Macedonian border, near Gevgelija. Macedonia is a key transit country in the Balkans migration route into the EU, with thousands of asylum seekers - many of them from Syria, Afghanistan, Iraq and Somalia - entering the country every day Getty Images Refugee crisis - in pictures An aerial picture shows the "New Jungle" refugee camp where some 3,500 people live while they attempt to enter Britain, near the port of Calais, northern France Getty Images Refugee crisis - in pictures A Syrian girl reacts as she helped by a volunteer upon her arrival from Turkey on the Greek island of Lesbos, after having crossed the Aegean Sea EPA Refugee crisis - in pictures Refugees arrive by boat on the Greek island of Lesbos after crossing the Aegean sea from Turkey Getty Images Refugee crisis - in pictures Beds ready for use for migrants and refugees are prepared at a processing center on January 27, 2016 in Passau, Germany. The flow of migrants arriving in Passau has dropped to between 500 and 1,000 per day, down significantly from last November, when in the same region up to 6,000 migrants were arriving daily.

The Government also committed to homing up to vulnerable children who had already reached Europe under the “Dubs amendment” but dropped the scheme after capping numbers at 350 in February.

It blamed local councils for failing to provide resettlement places, while defending the UK’s record providing £2.3bn for refugees in Syria and surrounding countries.

Babar Baloch, a spokesperson for the UNHCR, said the US has pledged to make 64,000 places available for Syrians and that efforts would continue amid court battles over Mr Trump’s attempts to reduce the programme.

Turkey now hosts 2.97 million Syrians and the number is growing as enforcement of an agreement struck with the EU to reduce boat crossings continues.

The deal, which came into effect a year ago, has slowed crossings over the Aegean Sea but resulted in 62,000 asylum seekers being trapped in Greece, where a Syrian man was found hung this week.

Crossings over the central Mediterranean Sea have continued to rise as smugglers take advantage of lawlessness and conflict in Libya to detain migrants and launch them packed into flimsy dinghies.

The vast majority of asylum seekers now arriving in Europe are taken to Italy by rescue ships, but they have also crossed by land and sea to Spain, and a fishing boat carrying 91 Syrian refugees, including 42 children, landed in Cyprus on Wednesday.

More than 28,000 asylum seekers have reached Europe by sea this year – more than 23,000 to Italy and 4,000 to Greece.