Claims that chemical weapons have been used in Syria should not become a pretext for a foreign military intervention in the country, Russian Deputy Foreign Minister Mikhail Bogdanov said on Saturday.
"If there is serious evidence of the use of chemical weapons in Syria, it should be presented immediately and not concealed," said Bogdanov, who is President Vladmir Putin's Middle East envoy, during a visit to Beirut.
"We must check the information immediately and in conformity with international criteria, and not use it to achieve other objectives. It must not be a pretext for an intervention in Syria," added Bogdanov.
On Thursday, US officials said for the first time that there was evidence the Syrian regime had likely used chemical weapons in small quantities, but emphasised that more investigation was necessary to confirm the suspicions.
US President Barack Obama warned Syria on Friday that using chemical weapons would be a "game changer," but also said Washington must act prudently, and establish exactly if, how and when such arms may have been used.
Obama, who had previously told Syrian President Bashar al-Assad the use of chemical weapons would cross a "red line," promised a "vigorous" US and international probe into the latest reports.
But he appeared wary of launching military action based on initial intelligence reports of chemical weapons use.
"I think all of us, not just in the United States but around the world, recognise how we cannot stand by and permit the systematic use of weapons like chemical weapons on civilian populations," he said as he met Jordan's King Abdullah II in the Oval office.
"We have to act prudently. We have to make assessments deliberately," he cautioned.
Russia, one of Syrian President Bashar al-Assad's staunchest allies, is firmly opposed to military intervention in Syria.
"We must know the truth and have proof and not rely on information reported in the media which is not supported by facts," Bogdanov said in Arabic on the Al-Manar television station of Lebanon's Hezbollah movement.
"We have the past experience of another violent intervention in Iraqi affairs under the pretext of the presence of nuclear weapons, and it turned out in the end that there was nothing," he added.
The experience of the US invasion of Iraq in 2003 looms large over claims of chemical weapons use in Syria, with critics claiming the allegations are being used as a pretext for international intervention in the conflict.
Bogdanov met on Saturday with the head of Hezbollah's parliamentary group, Mohammed Raad, a meeting the envoy described as "very useful," without adding details.
Hezbollah, a long-standing ally of the Assad regime, has dispatched fighters to Syria to battle alongside government troops, raising tensions inside Lebanon.