The United States warned Wednesday that it could take unilateral action if the United Nations fails to respond to a suspected chemical attack in Syria that has left scores dead, including children.

Axar.az reports that "When the United Nations consistently fails in its duty to act collectively, there are times in the life of states that we are compelled to take our own action," U.S. Ambassador Nikki Haley said.

The warning came during an emergency meeting of the UN Security Council called by France and Britain after the attack in the early hours on Tuesday on a opposition-held town in Idlib province.

Haley lashed out at Russia for failing to rein in its ally Syria, standing in the council chamber to hold up photographs of victims -- one showing a young child lying lifeless, a mask covering his face.

"How many more children have to die before Russia cares?" she asked.

"If Russia has the influence in Syria that it claims to have, we need to see them use it," she said. "We need to see them put an end to these horrific acts."

At least 72 people, among them 20 children, were killed in the strike on Khan Sheikhun, and dozens more were left gasping for air, convulsing, and foaming at the mouth, doctors said.