A host of top UN officials on Tuesday called on the divided UN Security Council to take stronger action to deal with the fallout from the two-year-old conflict, in which up to 100,000 people are believed to have died.
"The extremely high rate of killings nowadays -- approximately 5,000 a month -- demonstrates the drastic deterioration of the conflict," UN assistant secretary general for human rights Ivan Simonovic told a council meeting.
"In Syria today, serious human rights violations, war crimes and crimes against humanity are the rule," Simonovic declared.
Syria's UN ambassador Bashar Jaafari disputed the UN death toll as "unprofessionally sourced" and criticized the use of an American company to collect data.
He said each death was checked by name and date and cross-checked with at least three sources.
Nearly 1.8 million people are now registered with the United Nations in countries around Syria and an average of 6,000 people a day are now fleeing, UN High Commissioner for Refugees Antonio Guterres said.
"We have not seen a refugee outflow escalate at such a frightening rate since the Rwandan genocide almost 20 years ago," Guterres added.
More than two million Rwandans fled the 1994 genocide, in which radical Hutus killed some 800,000 Tutsis and moderate Hutus in a period of about three months.
Guterres said the acceptance of refugees by Lebanon, Iraq, Jordan and other countries was "saving hundreds of thousands of lives."
UN humanitarian chief Valerie Amos said the international community may have to consider cross-border operations to get aid into Syria.
Amos added that $3.1 billion was still needed for operations in and around Syria for the rest of the year.
She said four million people inside Syria need assistance.
Amos appealed for the lifting of bureaucratic obstacles but also the designation of "priority humanitarian routes" and prior notification of military offensives.
Amos said there should be "humanitarian pauses" to allow aid access and "cross-border operations, as appropriate."
UN leader Ban Ki-moon has since said that up to 100,000 people have been killed in Syria.
The conflict in Syria started in March 2011, when pro-reform protests turned into a massive insurgency following the intervention of Western and regional states.
The unrest, which took in terrorist groups from across Europe, the Middle East and North Africa, has transpired as one of the bloodiest conflicts in recent history.
As the foreign-backed insurgency in Syria continues without an end in sight, the US government has boosted its political and military support to Takfiri extremists.
Washington has remained indifferent about warnings by Russia and other world powers about the consequences of arming militant groups.
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