The top United Nations refugee official told the Security Council on Wednesday that the number of registered Syrians who had fled their homeland for safety elsewhere in the region could surpass one million by next month -- much sooner than expected -- and that the Syrian conflict threatens to overwhelm the international response.
"We are facing a moment of truth in Syria," the official, António Guterres, the United Nations high commissioner for refugees, told the Council at a closed session in remarks that were later published on his agency's Web site. "The humanitarian situation is dramatic beyond description. The refugee crisis is accelerating at a staggering pace."
Mr. Guterres was one of three senior United Nations officials who briefed the Security Council, painting what some diplomats later described as a chilling description of the fates of civilian victims of the nearly two-year-old uprising against President Bashar al-Assad. More than 70,000 people have been killed, more than two million have been displaced and more than four million need assistance.
The other speakers were Valerie Amos, under secretary general and emergency relief coordinator, and Zainab Hawa Bangura, a former health minister of Sierra Leone, appointed by Secretary General Ban Ki-moon last year as the United Nations' special representative on sexual violence in conflict.
Their remarks were not immediately disclosed publicly, but Britain's ambassador, Sir Mark Lyall Grant, told reporters that all three had given "very somber and disturbing briefings."
"We heard about, from Ms. Bangura, really for the first time, the widespread and systematic use of sexual violence by the regime," Sir Mark said.
Gérard Araud, France's ambassador, told reporters that "we are creating a Somalia in the heart of the Middle East."
The Security Council regularly receives updates on the conflict although it has been paralyzed on how to deal with it. Efforts by Western members that would authorize the use of force have been blocked by Russia and China, which have opposed outside military interference and have urged dialogue between Mr. Assad and his opponents.
Mr. Guterres said that last April, the agency registered 33,000 Syrians in the region and that as of Tuesday the figure was 936,000 across the Middle East and Africa, "nearly 30 times as many people as 10 months ago."
In December, when the agency was recalculating refugee flows, it projected 1.1 million refugees by June. Now, Mr. Guterres said, "if things continue to accelerate like this, it will take less than a month to reach that number."
Many Syrian refugees had not presented themselves for registration, which means his figures understate the magnitude of the problem. In Lebanon the agency documented 315,000 refugees, but the actual number probably exceeds 400,000. He said more than 300,000 Syrians had registered in Jordan but that the government estimated 400,000 had fled there.
In Turkey, 183,000 registered Syrians live in camps, and an estimated 100,000 unregistered Syrians live in urban areas. Iraq is now home to more than 100,000 Syrians, and Mr. Guterres said 37,000 Syrians had been registered in North Africa.
He also warned of the disruptions to Syria's half-million Palestinian refugees and that 30,000 had already fled, mainly to Lebanon, where sectarian tensions have been worsening.
Sectarianism was a theme sounded Wednesday by the leader of Hezbollah, the powerful Lebanese Shiite militant organization that has aligned itself with Mr. Assad. "We do not want to attack anybody," the leader, Hassan Nasrallah, said in a televised speech. "But at the same time, let no one miscalculate with us."
Hezbollah is facing increasing pressure over its support for Mr. Assad against an uprising that is largely drawn from Syria's majority-Sunni population. That position has left Hezbollah and its Shiite followers isolated and feeling vulnerable.
In the past week, Syrian rebels threatened to retaliate against Hezbollah for its increasingly overt military involvement in Syria, and reportedly lobbed a mortar into Hezbollah territory in Lebanon's northern Bekaa region; a Lebanese Sunni cleric also threatened attacks on Hezbollah.
Rick Gladstone reported from New York, and Anne Barnard from Beirut, Lebanon.
This article originally appeared in The New York Times.