More than two million Syrians have now fled their war-ravaged country, according to the UN refugee agency, marking the nearly 10-fold increase from a year ago.
In addition to the two million Syrians living as refugees, another 4.25 million people have been displaced within the country since the conflict began in March 2011, UN figures show.
"Syria is haemorrhaging women, children and men who cross borders often with little more than the clothes on their backs," the UNHCR said in a statement on Tuesday, pointing out that on September 3, 2012, it had registered just 230,671 Syrian refugees.
Century's 'great tragedy'
A total of 6.2 million Syrians have thus been displaced from their homes, a number without parallel in any other country and representing nearly a third of Syria's pre-war population of 20.8 million.
"Syria has become the great tragedy of this century," Antonio Guterres, the UN high commissioner for refugees, said in a statement, describing the situation in the country as "a disgraceful humanitarian calamity with suffering and displacement unparalleled in recent history".
The only solace, he said, "is the humanity shown by the neighbouring countries in welcoming and saving the lives of so many refugees".
In the past 12 months, almost 1.8 million people have flooded out of Syria, and an average of 5,000 continue to cross into neighbouring countries each day, UNHCR said, pointing out that on August 23, the number of Syrian children living as refugees topped one million.
The influx is placing an overwhelming burden on the host countries, UNHCR said.
At the end of August, about 716,000 Syrian refugees were registered or in the process of being registered in Lebanon, 515,000 in Jordan, 460,000 in Turkey, 168,000 in Iraq and 110,000 in Egypt, according to the agency's numbers.
Al Jazeera's correspondents reporting from Iraq and Turkey say funding for the refugees in the surrounding countries in now rapidly depleting as well.
Al Jazeera's Imran Khan, reporting from the Kawergosk refugee camp in northern Iraq, said that almost 1,000 refugees had been entering the country daily.
He said the financial constraints were weighing heavy on the Iraqi government as well.
Al Jazeera's Anita McNaught, reporting from the Kilis refugee camp in Turkey, said the crisis in Syria had "blown everyone's red lines".
"I remember a time when Turkey said that it could not handle more than 100,000 refugees," she said.
She said the country was now accommodating almost 500,000 people and that it was costing the country close to $2bn.
"The Turks want to go to Geneva to ask for more funding to support refugees," she said, adding that the country is now only taking in refugees that it can accommodate, to avoid being destabilised by the crisis.
In a related development, a 52-year-old married Palestinian woman who lived in Syria was found dead on board a boat carrying more than 100 migrants that was intercepted by the Italian coast guard off the Sicily coast on Monday afternoon, according to the Italian news agency ANSA.
A total of 104 refugees, the majority Syrian and Egyptian, were on board the boat which was also carrying a number of children, some as young as three.
Last week, a Syrian refugee travelling by boat to Italy gave birth to a boy during an eight-day voyage at sea.
She was one of 355 refugees travelling on two overcrowded boats.
Thousands of migrants have arrived in the past few weeks in Sicily, many of them coming from Egypt or Syria, among migrants from sub-Saharan Africa.
The Italian Interior Ministry estimates that 3,000 Syrian migrants arrived in Italy from the beginning of this year up until the end of August.