As President Donald Trump ramped up his threats of military action against Syria this week, the Syrian military has been repositioning some air assets to avoid the fallout from possible missile strikes, US officials told Reuters on Wednesday.
The officials declined further comment and it was not clear whether the Syrian moves would impact US military planning for potential action against Syria over a suspected poison gas attack.
But the Syrian moves could limit damage the United States and its allies might be able to inflict on Syrian President Bashar al-Assad's military.
A similar assessment was delivered earlier on Wednesday by the Syrian Observatory for Human Rights, a Britain-based war monitor, which said that pro-Syrian government forces were emptying main airports and military air bases.
For days, Trump has been warning Syria and its backers, Russia and Iran, over the suspected gas attack. On Wednesday, he offered the clearest sign yet of his willingness to attack Syria, declaring that missiles "will be coming" and criticizing Moscow for standing by Assad.

Army vacates main defence buildings

Syria's army has evacuated key defence buildings in Damascus following intelligence they might be targeted in a Western strike in response to an alleged chemical attack, a monitor said Wednesday.
"The buildings of the ministry of defence and the army headquarters have been empty for two days," the Syrian Observatory for Human Rights monitoring group said.
"The Russians told the Syrian army's leadership they had intelligence on possible US and French targets in Syria," Observatory head Abdel Rahman said.
According to the Russian intelligence, the United States is pushing for possible strikes to target the ministry of defence and army headquarters in Damascus, he said.
The intelligence indicated they were also aiming to strike military airports and bases, the Observatory said.
According to the same Russian intelligence, France would like targets to include President Bashar al-Assad's chemical facilities.
These would be the Syrian Scientific Studies and Research Center in Jamaraya, just north of the capital, and chemical warfare headquarters in Damascus.
Paris would be pushing for a strike on the Dumair military airport, which is suspected of having been the launchpad for Saturday's alleged chemical attack.
There was no immediate confirmation from the Damascus regime.
Rescuers say more than 40 people were killed in Saturday's alleged toxic gas attack.
Last year, Trump launched a cruise missile strike against a Syrian air base in retaliation for a sarin attack the United Nations later pinned on Assad.
More than 350,000 people have been killed in Syria's conflict since it started in 2011 with the brutal repression of anti-government protests. 
It has since spiralled into a complex war involving world powers.