With the global war on Syria headed for a sixth year, UN agencies on Tuesday appealed for $7.73 billion in funding to help 22.5 million people affected by the conflict.

With the global war on Syria headed for a sixth year, UN agencies on Tuesday appealed for $7.73 billion in funding to help 22.5 million people affected by the conflict.

The appeal for funds from UN member-states covers help for 13.5 million Syrians displaced inside the country and 4.7 million who have fled across the border to neighboring countries.

The aid will also reach some four million people in Turkey, Jordan and Lebanon who are hosting millions of Syrian refugees, said a UN statement.

International donors will be asked to come forward with large pledges at a conference on Syria's humanitarian crisis in London on February 4.

"After nearly six years of brutal conflict and political paralysis, the Syrian people need our help more than ever," said UN aid chief Stephen O'Brien.

UN High Commissioner for Refugees Filippo Grandi stressed that Syria's neighbors were shouldering the biggest burden from the refugee crisis and said funding must be directed at them.

More than a million refugees, many from Syria, crossed into Europe last year after conditions in camps deteriorated, with cuts to food rations and other aid.

Last year, UN agencies asked for $8.4 billion from governments worldwide to fund the Syrian aid effort, but received only $3.3 billion of that amount.

The appeal for Syria is part of a wider 2016 humanitarian appeal, asking for $20.1 billion to reach 87 million people in need of aid around the world.