The clarification came after panel member Carla Del Ponte told Swiss-Italian television Sunday U.N. experts have "strong, concrete suspicions, but not yet incontrovertible proof, of the use of sarin gas" by rebel groups, The Hill reported.
"The Independent International Commission of Inquiry on the Syrian Arab Republic wishes to clarify that it has not reached conclusive findings as to the use of chemical weapons in Syria by any parties to the conflict," the U.N. said in a statement. "As a result, the commission is not in a position to further comment on the allegations at this time.
A growing number of countries, have said they believe government forces have used chemical weapons, which would cross President Obama's "red line" and could prompt greater U.S. involvement in the 2-year-old civil war.
The statement said commission Chairman Paulo Sergio Pinheiro "reminds all parties to the conflict that the use of chemical weapons is prohibited in all circumstances under customary international humanitarian law."
Rebels and officials from President Bashar Assad's government have denied using chemical weapons.
Also Monday, rebels said they shot down a government helicopter, killing eight troops.
The development followed a report Assad told Russia he ordered his army to deploy rocket batteries aimed at Israel in response to airstrikes on Damascus, aides said.
The opposition Syrian Observatory for Human Rights, based in Britain, posted video on its website Monday showing combatants in front of what appeared to be wreckage of a helicopter, The New York Times reported.
The observatory said eight government security troops were on the helicopter in the eastern part of the country.
In a chain of explosions that rocked Damascus before dawn Sunday, at least 100 Syrian soldiers were killed, an unnamed Syrian doctor at the military's Tishreen Hospital said in a report in Times.
The report that Assad ordered rocket batteries set up to aim at Israel came from the Almiadin television station in Lebanon.
Assad said he would allow Palestinian organizations operating in his country to wage attacks against Israel from the Golan Heights, Syrian state television reported.
"The Israeli aggression opens the door to all possibilities and confirms the organic correlation between expiatory terrorist groups and the Israeli enemy," Syrian Information Minister Omran Zoubi said in a report carried by the state news agency SANA.
Syrian Deputy Foreign Minister Faisal al-Mekdad told CNN: "When they attack, this is a declaration of war. This is not something that is [new]. We dealt with this on several occasions and we retaliated the way we wanted, and the retaliation was always painful to Israel, and they will suffer again."
The Israeli army raised its level of alert along its northern border with Syria, Israel Radio said.
An unnamed senior Israeli official said the goal is to convey to Assad that Israel's sole interest is to prevent advanced weaponry from reaching the Lebanese militant group Hezbollah, not intervening in Syria's civil war or help rebels topple his regime, Haaretz said.
The airstrikes were aimed at destroying advanced Iranian-made Fatah 110 missiles said to be en route to Hezbollah, reports said.
Two Iron Dome missile defense batteries were positioned near Israel's northern border in response to "ongoing situational assessments," an Israeli military spokesman said.
The White House reiterated a position President Obama stated Saturday that Israel had a right to defend itself.
"The Israelis are justifiably concerned about the threat posed by Hezbollah obtaining these advanced weapon systems," spokesman Josh Earnest told reporters.