"They agreed the event would be a major moment in tackling what is now widely accepted as the world’s biggest humanitarian crisis and that all countries in attendance should look to at least double their 2015 financial contribution to the crisis, to better meet the great need identified in the UN appeals," a spokesperson of the British Prime Minister’s Office said in a Wednesday statement.
Prime minister Cameron also held phone talks with King Salman of Saudi Arabia on Wednesday.
"Both leaders agreed the Syria donors conference would be an important opportunity to boost support to refugees in the region, including through significant additional funding," the Wednesday statement said.
According to the United Nations, over six million Syrian people have been displaced amid an ongoing civil war in the country, while 65 percent of the population lives in poverty.
Syria has been mired in a civil war since 2011, with government forces loyal to President Bashar Assad fighting a number of opposition factions and extremist groups, including Islamic State (ISIL, also known as Daesh).