In a statement, the White House said that Assad and his men will have to pay a heavy price if they carry out another attack in Syria.

"As we have previously stated, the United States is in Syria to eliminate the Islamic State of Iraq and Syria. If, however, Mr Assad conducts another mass murder attack using chemical weapons, he and his military will pay a heavy price." the statement read.

Meanwhile, Nikki Haley, US' representative to the United Nations tweeted that Assad will be held responsible for any further attack in Syria.

Haley also warned Russia and Iran of severe consequences if they lend their support to Assad's cause.

"Any further attacks done to the people of Syria will be blamed on Assad, but also on Russia & Iran who support him killing his own people," he tweet read.

Earlier, in the month of April, the US blamed Syria for carrying out a nerve gas attack, in which dozens, including children lost their lives.

Syria however has denied all allegations.

Following the attack, the US launched 59 Tomahawk cruise missiles at Shayrat airfield, which according to the White House was used to store chemical weapons.

The US attack also lead to the death of nine civilians.

Image: PHC C.M. Fitzpatrick - United States Department of Defense/Wikipedia