Russian Ambassador Alexander Zasypkin, in comments broadcast on Tuesday evening, said he was referring to a statement by Russian President Vladimir Putin and the Russian armed forces chief of staff.
The Russian military said on March 13 that it would respond to any US strike on Syria, targeting any missiles and launchers involved in such an attack. Russia is Syrian President Bashar Assad's most powerful ally.
Meanwhile Wednesday, Prime Minister Benjamin Netanyahu asked government ministers not to make public statements on the current security situation, explaining that "this is a sensitive reality."
The United States and its allies are considering whether to hit Syria over a suspected poison gas attack that medical relief organizations say killed dozens of people in the rebel-held town of Douma near Damascus on Saturday.
"If there is a strike by the Americans, then...the missiles will be downed and even the sources from which the missiles were fired," Zasypkin told Hezbollah's al-Manar TV, speaking in Arabic. He also said a clash "should be ruled out and therefore we are ready to hold negotiations."
Zasypkin added that the United States and its allies saw the recent developments in eastern Ghouta as their failure and were trying to delay the results of the three-way summit held between the Russian, Iranian and Turkish leaders in Ankara.
Russia and the United States blocked attempts by each other in the UN Security Council on Tuesday to set up international investigations into chemical weapons attacks in Syria.
According to Syrian report, the Assad army is preparing for a possible American attack. French daily Le Figaro reported Wednesday that the Syrian army was evacuating the Dumayr airbase in the Qalamun Mountains on the Syrian-Lebanon border. The soldiers and missiles from that base, the French paper said, were being transferred to the Russian-operated Khmeimim airbase.
According to the French report, the planes that carried out the chemical attack in the rebel enclave in eastern Ghouta took off from the Dumayr airbase.
US President Donald Trump on Tuesday cancelled a planned trip to Latin America later this week to focus instead on responding to the Syria incident, the White House said. Trump had on Monday warned of a quick, forceful response once responsibility for the Syria.
Opposition-affiliated media outlets in Syria reported Tuesday that the Assad regime and its allies were taking precautions in bases across the country. The Syrian Observatory for Human Rights reported that Syrian regime forces and the militias supporting it were on a heightened state of alert in all military bases and posts across the country, including in Damascus.
In letters issued by senior Syrian regime officials, the forces were ordered to maintain a heightened state of alert for 72 hours. The report added that the Shiite militias supporting the Assad regime had started preparing their bases for a strike that could take place at any moment. Sky News Arabia reported that Iranian fighters and Hezbollah members had evacuated their posts in the city of Abu Kamal, near the Iraqi border.
European airspace authorities are warning aircraft to be careful over the next 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 operations needed to consider the possibility of air or missile strikes into Syria.
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."
Rival US and Russian resolutions to determine responsibility for chemical weapons attacks in Syria suffered defeats at the United Nations on Tuesday, a result that the Russian ambassador said the Trump administration wanted so it can "justify the use of force against Syria."
The Security Council also rejected another Russian-drafted resolution that would have welcomed an investigation by the Organization for the Prohibition of Chemical Weapons of allegations of a weekend chemical attack in the suburbs of Syria's capital. The US, Britain and France opposed the measure, saying that the investigators are already headed there and that the text didn't include a new way to assess blame for chemical attacks.
After the defeat of Russia's second resolution, Russian Ambassador Vassily Nebenzia said to US Ambassador Nikki Haley: "I would once again ask you, once again beseech you, to refrain from the plans that you're currently developing for Syria."
The threats of US military action against Syria "should make us seriously worried, all of us," Nebenzia said.
Reuters, Liad Osmo and Rachel Cadars contributed to this report.