"All of what some media outlets reported about airstrikes by US war jets on targets in the al-Raqqa province is totally untrue," the military said.
The news came just a day after the Syrian air force killed as many as 31 IS militants in a total of 26 airstrikes against their positions in al-Raqqa, Xinhua reported. The US has been aiding the Kurds in Iraq against the IS militants there, backing them up with airstrikes against the positions of the IS.
On Monday, media reports said the Kurdish militias succeeded in recapturing the al-Mosel Dam from the IS with the help of the US Air Force.
The IS, previously known as the Islamic State in Iraq and Greater Syria (ISIS), has recently proclaimed the establishment of an "Islamic Caliphate".
The group, led by Abu Bakr al-Baghdadi, who commands tens of thousands of fighters, said their goal was to establish an Islamic state in Iraq and Syria.
Over 160,000 people in Syria have been killed and millions displaced due to the violence since March 2011.