BEIRUT -- Russian lawmakers say Moscow would view a U.S. airstrike on Syria as a war crime that could trigger a direct military clash between the two former Cold War adversaries.
Russia's ambassador to Lebanon went even further, saying any missiles fired at Syria would be shot down and the launching sites targeted -- a stark warning of a potential major confrontation in Syria.
U.S. President Donald Trump threatened military action after last weekend's suspected chemical attack on a rebel-held town near Damascus, which activists and rescuers say killed at least 40 people. The Syrian government and its ally Russia deny that such an attack happened.
Trump took to Twitter on Wednesday to respond to the latest Russian warnings, saying missiles "will be coming."
"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!"' Trump tweeted on Wednesday. "You shouldn't be partners with a Gas Killing Animal who kills his people and enjoys it!"
Russia's Foreign Ministry responded by saying "smart" missiles would destroy evidence of a chemical attack. In a Facebook post, spokeswoman Maria Zakharova wondered if the "original idea" is to "use the smart missiles to sweep the traces of the provocation under the rug."
Asked earlier about Moscow's reaction to a possible U.S. strike on Syria, Kremlin spokesman Dmitry Peskov said Russia still hopes that all parties in the conflict will refrain from taking "steps that could gravely destabilize the fragile situation in the region."
State news agency RIA Novosti on Wednesday quoted Andrei Krasov, deputy chairman of the State Duma's defence committee, as saying that Russia will treat a U.S. airstrike on Syria "not just as an act of aggression but a war crime of the Western coalition."
Vladimir Shamanov, a retired general who heads the defence affairs committee in the lower house of parliament, said in televised remarks Tuesday that a U.S. strike in Syria could hurt Russian servicemen and trigger retaliation.
He said that Russia has "the necessary means for that, and the Americans and their allies know that quite well."
Shamanov emphasized that a retaliatory Russian strike could target U.S. navy ships and aircraft. He added that the use of nuclear weapons is "unlikely."
Russian Ambassador to Lebanon Alexander Zasypkin, meanwhile, told Hezbollah's Al-Manar TV station that any missiles fired at Syria would be shot down. He said he was referring to a statement by Russian President Vladimir Putin and the Russian armed forces chief of staff.
"If there is a strike by the Americans, then... the missiles will be downed and the source of the missiles targeted," Zasypkin said.
Meanwhile, European airspace authorities warned aircraft to be careful over the coming days when flying close to Syria because of possible military action against President Bashar Assad's forces.
The Eurocontrol airspace organization said that the European Aviation Safety Agency had sent a "Rapid Alert Notification" that flight operators needed to consider the possibility of air or missile strikes into Syria.
U.S. officials have consulted with global allies on a possible joint military response to Syria's alleged poison gas attack.
In a notice posted to Eurocontrol's website, EASA said: "Due to the possible launch of air strikes into Syria with air-to-ground and/or cruise missiles within the next 72 hours, and the possibility of intermittent disruption of radio navigation equipment, due consideration needs to be taken."
