President Barack Obama said Wednesday that the United States is still investigating whether chemical weapons were used in Syria and reiterated his pledge that their use by President Bashar Assad's government would be a "game changer" for U.S. policy.
"We have to make sure that we know exactly what happened, what was the nature of the incident, what we can document, what we can prove," Mr. Obama said at a Jerusalem news conference with Israeli Prime Minister Benjamin Netanyahu. "I won't make an announcement today about next steps, because I think we have to gather the facts," he said.
In the past, Mr. Obama has called any use of such weapons by Mr. Assad a "red line."
The president's statements came after the Syrian government and the opposition repeated their accusations that the other side used chemical weapons in an attack Tuesday on a village near Aleppo. Both sides asked the United Nations to send a team to investigate the incident.
Although the facts have not been established yet, Mr. Obama said, he was "deeply skeptical of any claim that it was the opposition that used chemical weapons," because only the regime has the capacity to carry out such an attack. The rebels said the chemicals were delivered on a Scud missile.
Mr. Obama also defended his administration's reluctance to intervene directly to stop the slaughter in Syria, telling an Israeli reporter, "It is incorrect for you to say that we have done nothing."
The United States, he said, had helped mobilize the world to isolate Mr. Assad, provided hundreds of millions of dollars in humanitarian assistance, supported and recognized the Syrian opposition and worked with other nations to "move towards a political transition."
Mr. Obama's comments, his first since the chemical weapons reports, were backed up by Robert Ford, the U.S. ambassador to Syria, who said at a House hearing Wednesday that "so far we have no evidence to substantiate the report that chemical weapons were used yesterday. But I want to underline that we are looking very carefully at these reports," the ambassador said. "We are consulting with partners in the region and in the international community."
Mr. Ford did not respond to repeated House Foreign Affairs Committee members' queries about what action the administration would take if Mr. Assad were proven to have used chemical weapons. "I absolutely do not want to go into hypotheticals," he said. "I do want to underline that we take these reports and these possibilities very seriously, and we are using all of our available means to determine exactly what has happened."
The Britain-based Syrian Observatory for Human Rights, a pro-opposition organization, said 26 people, including 16 Syrian soldiers, died in the attack Tuesday. But the observatory's director, who uses the pseudonym Rami Abdulrahman, said he could only "confirm that there was a rocket attack, but not that any chemicals were used."
Photographs posted online by the official Syrian Arab News Agency showed alleged victims in hospital beds, flanked by medical staff in surgical masks. State television featured an interview with an elderly man wearing a face mask and a white bandage on his forehead. "They fired a missile, and it exploded with something like a powder," the man said.
In the same TV report, a doctor said the patients appeared to have been exposed to "phosphorus material or some poisonous material," which he said had led to "heavy vomiting and difficulty in breathing, almost appearing like extreme suffocation cases."
Syria is known to possess large arsenals of the deadly nerve agents sarin and VX. Symptoms of both include vomiting, and death is usually caused by asphyxiation, as muscle paralysis impedes breathing. Both can contaminate through inhalation or skin contact, even with clothing worn by victims.
Intelligence reports in December that Syrian military units were moving toward possible activation of chemical arms led to a direct warning from Mr. Obama and subsequent administration assurances that the weapons were secure.
U.N. Secretary-General Ban Ki-moon's office said he was studying a written request from the Syrian government, backed by Russia, for an investigation into its claim of chemical weapons use by the rebels.
France and Britain countered with an effort to get as many Security Council members as possible to sign a letter asking Mr. Ban to open a wider investigation into chemical weapons use in Syria. No evidence that such weapons have been used was presented.
In addition to concerns about any use of chemical weapons against the Syrian people, Mr. Obama said the administration shared "Israel's grave concern about the transfer of chemical or other weapons systems to terrorists, such as [the Lebanese group] Hezbollah, that might be used against Israel."