The Assad regime in Syria appears to be taking the initial steps necessary to launch a chemical weapons attack, the White House said in a statement late on Monday.

The actions, if taken, would mean Assad and his government would “pay a heavy price,” the statement issued by White House Press Secretary Sean Spicer reads.

According to Spicer, the preparations that are underway would lead to an attack that “would likely result in the mass murder of civilians, including innocent children.”

The statement is intentionally unclear what specific repercussions would be dealt to Assad, but the Trump Administration has established a clear precedent that any use of chemical weapons in Syria will be met with a military response. The most recent mass chemical weapons attack attributed to Assad and his regime on April 4, 2017, led to a cruise missile attack on military targets of the Syrian regime at the Shayrat Airbase in Syria.

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The Syrian regime continues to deny any involvement in the April attack, which killed more than 80 men, women, and children.

The White House chose to issue the statement following intelligence reports showing precursor elements to a sarin gas attack being prepared by the regime, a non-government source told the Associated Press.

The U.S. has also engaged a number of targets in Syria belonging to Iranian surrogates it says are threatening U.S. allies on the ground, showing a willingness to operate outside of any strict campaign against the Islamic State. Speaking late last night on Twitter, U.S. Ambassador to the United Nations Nikki Haley issued a stern warning to Assad allies Russia and Iran as well:

If such reports are true, a measured U.S. military response is the likely outcome. The previous air strikes on Shayrat Airbase in April were noted for striking mostly hardened structures containing military equipment, but leaving the runways themselves largely intact, allowing the regime to launch aircraft from the site mere days later. This led some to question the efficacy of such a strike.

It may be that the U.S. erred by not doing more to render the facility inert. Or, a more likely scenario, the runways were left intact should they eventually be needed to facilitate an airfield seizure in the event of an American invasion or special operations incursion.

Image courtesy of the Department of Defense