Pro-government forces in Syria are emptying main airports and military air bases over possible U.S. strikes, the Syrian Observatory for Human Rights, a Britain-based war monitor, said on Wednesday.
The Syrian military has repositioned some air assets to avoid the fallout from potential missile strikes, U.S. officials confirmed to Reuters on Wednesday.
The officials declined further comment and it was not clear whether the Syrian moves would impact U.S. military planning for potential action against Syria over a suspected poison gas attack.
U.S. President Donald Trump said in a Tweet on Wednesday that American missiles "will be coming" to Syria following a suspected chemical weapons attack on Sunday. The Syrian army could not be immediately reached for comment.
Trump was reacting to a warning from Russia on Tuesday that any U.S. missiles fired at Syria over the deadly assault on a rebel enclave would be shot down and the launch sites targeted.
"Russia vows to shoot down any and all missiles fired at Syria. Get ready Russia, because they will be coming, nice and new and 'smart!'," Trumpwrote in a post on Twitter.
"You shouldn't be partners with a Gas Killing Animal who kills his people and enjoys it!" Trump tweeted, referring to Moscow's alliance with Assad.
In response, Russia's Foreign Ministry said in a Facebook post that "smart missiles should fly towards terrorists, not towards the lawful government".
Foreign Ministry spokeswoman Maria Zakharova said any U.S. missile strike could be an attempt to destroy evidence of the reported gas attack in the Syrian town of Douma, for which Damascus and Moscow have denied any responsibility.
In Damascus, the foreign ministry accused the United States, which has supported some rebel groups in the Syrian civil war, of using "fabrications and lies" as an excuse to hit its territory.
"We are not surprised by such a thoughtless escalation by a regime like the United States regime, which sponsored terrorism in Syria and still does," the state news agency SANA cited an official source in the ministry as saying.
After the Douma attack, the insurgent group dug in there - Jaish al-Islam - finally agreed to withdraw. That sealed a major victory for Assad in the war, crushing a protracted rebellion in the eastern Ghouta region near the capital Damascus.
Want to enjoy 'Zen' reading - with no ads and just the article? Subscribe todaySubscribe now