Julian Borger

Washington: The White House has declared that it believes Bashar Al Assad’s regime is preparing to carry out another chemical weapons attack, and warned that the Syrian leader and his military would “pay a heavy price” if it went ahead.

The unusual public warning on Monday night appeared to be intended to deter the regime from repeating its use of chemical weapons against rebel-held cities and towns. It may also have been aimed at the regime’s backers in Moscow and Tehran, who have resolutely backed Al Assad and denied the regime’s responsibility for chemical weapons use.

US Central Command, which oversees operations in the Middle East, said in a statement: “For this matter, we have no information to add to what has already been stated.”

Several US news outlets quoted unnamed US military sources as saying they had been taken by surprise by the announcement and had no independent knowledge of chemical weapons preparations. However, intelligence on any such Syrian activities is likely to have been closely held.

The US ambassador to the UN, Nikki Haley, tweeted: “Any further attacks done to the people of Syria will be blamed on Al Assad, but also on Russia and Iran who support him killing his own people.”

On 6 April, Donald Trump ordered a salvo of 59 Tomahawk missiles against a Syrian airbase alleged to have been the launching point for a sarin attack that killed at least 80 people three days earlier in the town of Khan Sheikhoun.

Russians were present at the Shayrat base, near Homs, but US planners ensured that the missiles used in the night-time strike fell well away from the Russian compound.

In a bluntly worded statement released late on Monday night, the White House said: “The United States has identified potential preparations for another chemical weapons attack by the Al Assad regime that would likely result in the mass murder of civilians, including innocent children.

“The activities are similar to preparations the regime made before its April 4, 2017 chemical weapons attack,” the White House said. “As we have previously stated, the United States is in Syria to eliminate the Islamic State of Iraq and Syria [Daesh]. If, however, Mr [Al] Assad conducts another mass murder attack using chemical weapons, he and his military will pay a heavy price.”

Although the focus of US military operations in the region is the defeat of Daesh in its two major strongholds, Mosul in Iraq and Raqqa in Syria, the Trump administration has showed itself willing to act if the Al Assad regime carries out a major chemical weapons attack.

US forces in Syria have also been empowered to defend themselves and their allies against attack, which has led to a string of recent clashes with pro-regime forces competing for the same territory.

“The White House must have solid intelligence about a possible Syrian sarin attack but why they chose to send [a] message to [Al] Assad and Putin via press release isn’t clear,” Daryl Kimball, the head of the Arms Control Association said in a tweet.

Kimball warned that the risk of coming into conflict with Russian forces in the event of another punitive US strike was higher now than it was in April.

Alexey Khlebnikov, a Russian Middle East expert said on social media: “This US move definitely does not help building cooperation [with Russia]. Expect [a] Moscow reaction like ‘US again gives no evidence, makes things worse’.”

Guardian News & Media Ltd.