The White House issued a statement Monday night indicating that they believed Syrian dictator Bashar al-Assad was planning a new chemical strike, and they warned that the U.S. would not stand by and allow that to happen without retaliation.

"The United States has identified potential preparations for another chemical weapons attack by the Assad regime that would likely result in the mass murder of civilians, including innocent children," the statement read.

"The activities are similar to preparations the regime made before its April 4, 2017, chemical weapons attack," it continued. "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 from White House press secretary Sean Spicer did not indicate what the Syrian preparations were or describe what repercussions President Donald Trump was prepared to order in retaliation.

U.S. Ambassador to the United Nations Nikki Haley made an additional statement on social media that notably added Iran and Russia as accessories to the potential war crime.

"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," she posted.

In April, Trump ordered a tomahawk cruise missile attack on the airbase from which officials say Assad launched a chemical attack on his own citizens. The world was horrified at the images and videos that surfaced showing civilians gasping for air as they asphyxiated from the chlorine gas.

Assad and his allies, including Russian President Vladimir Putin, have strenuously denied that he ordered the attack and have instead pinned the blame on anti-Assad rebels.

The issue further drove a wedge between the U.S. and Russia when a United Nations resolution condemning the chemical attack was vetoed by the Russians because, according to them, it unfairly blamed Assad without enough evidence.

Haley directly addressed the Syrians in a speech after the veto.

“The United States is watching your actions very closely,” she warned. “The days of your arrogance and disregard of humanity are over. Your excuses will no longer be heard. I suggest you look at this vote very carefully and heed this warning."

More recently, the U.S. shot down a Syrian warplane that had attacked allied forces, precipitating condemnation and a warning from Russia about further attacks against Assad.