UNITED NATIONS -- Syria's UN ambassador vehemently denied his government used chemical weapons on its own people in March, adding that Syrian officials were the first to request the UN investigate the incident just hours after it was reported.
"The Syrian government has been cooperating intensively with the secretary-general as well as with his senior officials," said Bashar Ja'afari, during an hourlong news conference Tuesday at UN headquarters in New York. "Yet you may have heard many trumped up charges and fraudulent accusations."
He spoke as President Barack Obama edged closer to more decisive action in the 2-year-old civil war that began in March 2011 as part of the Arab Spring. Obama said the confirmed use of chemical weapons by the government of Syrian President Bashar Assad would be a "game-changer" for the United States.
Among options being considered by the Obama administration are providing more support -- even arms -- to the rebels aiming to oust Assad. The New York Times reported that the Pentagon has drafted a list of options including airstrikes, commando raids and a no-fly zone.
"So when I've said the use of chemical weapons would be a game changer, that wasn't unique to -- that wasn't a position unique to the United States, and it shouldn't have been a surprise," he said at a news conference Tuesday. "And what we now have is evidence that chemical weapons have been used inside of Syria, but we don't know how they were used, when they were used, who used them; we don't have chain of custody that establishes what exactly happened."
Just who used chemical weapons is at the heart of the matter, as are establishing the facts about when they were used.
A 15-member team of UN experts has been stymied for weeks from entering the area where the chemical weapons are believed to have been used in Aleppo due to a diplomatic impasse.
Though Assad's government requested the inspections, it has denied access to the team partly because the team -- at the request of British and French diplomats -- wanted the investigation to expand to reported incidents in other parts of Syria, Ja'afari said.
"The Syrian government did not close the doors on the United Nations and the investigation missions to look into any other allegations, but the principles of respecting international law and the charter of the United Nations require a strict respect of the sovereignty of member states," he said.
"We have victims," he continued. "We have bodies. We have wounded. We have footage. We have blood samples. We have all the tools necessary to prove that chemical weapons were used . . . and some people are still turning around looking for some artificial fronts to investigate something else. Let's start with what we have as facts."
The barbs came in the wake of an apparent attempt to kill Syria's prime minister, Wael Nader al-Halqi, who was in Damascus when a car bomb exploded near his convoy, killing a bodyguard, according to media reports.
It also comes as the crisis worsens apace.
The war has claimed as many as 70,000 lives and sparked a flood of millions of refugees and internally displaced people, by UN estimates. As many as 1.3 million refugees have been absorbed by neighboring countries.