This comes after the British immigration minister said only two dozen Syrians have been given refuge in the UK since January.
The UN Refugee Council said it was immensely disappointed with the figure and the UK’s commitment.
"We are appealing for a meaningful increase in the number of resettlement opportunities. We are asking for [an additional] 100,000 vacancies globally, and we hope that all countries will increase their quotas," António Guterres, the UN high commissioner for refugees (UNHCR), said in a statement on Friday.
The UK's special relocation program for vulnerable refugees has been set up by Prime Minister David Cameron in the face of millions of desperate people fleeing the conflict in Syria.
According to the most recent figures, nearly three million Syrians have fled the country since the conflict began there more than three years ago.
The developments come as the number of people driven from their homes by conflicts and crises worldwide has topped 50 million for the first time since the second World War.
The UN refugee agency says there were over 51 million displaced people in 2013. That means a full six million higher than the previous year.
The agency's annual trends report says the situation in Syria is especially dramatic.
More than six million Syrians have been internally displaced.
New crises in South Sudan, the Central African Republic and Iraq have added to the number.
Palestinians, Afghans and Somalis, who fled in previous years, still make up the bulk of the global refugee count.
SHI/SHI