The number of Syrians who have fled their country since a deadly civil conflict erupted two years ago has hit one million, the UN's refugee agency said Wednesday.
"With a million people in flight, millions more displaced internally, and thousands of people continuing to cross the border every day, Syria is spiralling towards full-scale disaster," UN High Commissioner for Refugees Antonio Guterres said in a statement.
"We are doing everything we can to help, but the international humanitarian response capacity is dangerously stretched. This tragedy has to be stopped."
The UNHCR said the one million figure comprised both registered refugees and those awaiting registration, and that the count was based on fresh data received from its offices in the Middle East.
The agency previously had estimated that numbers would reach 1.1 million by June but said Wednesday that it would adjust that figure.
The exodus has intensified this year, the UNHCR said, with 400,000 Syrians fleeing their country since January 1.
Only a year ago, the UN agency had only registered 33,000 refugees.
Syrian President Bashar al-Assad's forces fiercely cracked down on what were initially unarmed protests inspired by the Arab Spring but the crisis has since escalated into a deadly civil war.
The UN said the latest refugees "arrive traumatised, without possessions and having lost members of their families." Around half of the refugees are children, the majority under the age of eleven.
Over 70,000 people have been killed since March 2011, according to the United Nations.
Most of the anti-Assad rebels are Sunni Muslims, while the ruling clan and many of its most fervent supporters are from the Alawite minority, an offshoot of Shiite Islam.
The refugees have fled primarily to Lebanon, Jordan, Turkey, Iraq and Egypt, but increasingly they are trying to reach North Africa and Europe, the UNHCR said.
"This number translates into one million people who are dependent on the generosity of host countries, the response of humanitarian agencies and the financial support of governments and individuals," said Guterres.
He underlined the impact of the numbers, with Lebanon's population having increased by as much as 10 per cent and Jordan’s energy, water, health and education services being strained to the limit.
Turkey has spent over $600 million setting up 17 refugee camps, with more under construction.
Iraq, already struggling with a million internally displaced people, has received over one hundred thousand Syrian refugees in the past year.
"These countries should not only be recognised for their unstinting commitment to keeping their borders open for Syrian refugees, they should be massively supported as well," said Guterres.
The UNHCR chief is due to travel to the region later this week to visit the agency's operations in Turkey, Jordan, and Lebanon.