Washington (AFP) - Coming closer to embracing regime change in Syria, the US ambassador to the United Nations said that with President Bashar al-Assad in power, Syria will not know peace, CNN reported Sunday.

"There's not any sort of option where a political solution is going to happen with Assad at the head of the regime," Nikki Haley told "State of the Union" program.

"It just -- if you look at his actions, if you look at the situation, it's going to be hard to see a government that's peaceful and stable with Assad."

Haley did not say the United States had changed its policy.

Her words, however, came a day after she said Washington was ready to take additional action after a solo US strike on a Syrian air base.

The base was used in the Syrian attack in Khan Sheikhun in rebel-held Idlib province, whose victims included 27 children.

US President Donald Trump has signaled a startling about-turn toward Assad, who many in the international community hold responsible for Tuesday's horrific events.

If confirmed to be a chemical attack, this would be among the worst such incidents in Syria's civil war, which has killed more than 320,000 people since it began in March 2011.

Syria officially relinquished its chemical arsenal and signed the Chemical Weapons Convention in 2013 to avert military action after it was accused of an attack outside Damascus that killed hundreds.

But there have been repeated allegations of chemical weapons use since.