Israel's Defence Minister Avigdor Lieberman said on Monday that Israel will strike back if Syria uses Russian S-300 missiles against its air force.
"If someone would shoot at our planes, we will destroy it", said Lieberman.
Speculation has mounted in recent weeks that Russian Federation could deploy the advanced S-300 anti-aircraft missile defense system to Syria, following a US-led airstrike on Syrian military sites and another earlier strike on an Iranian-operated air base in Syria widely attributed to Israel.
The Damascus sky lights up missile fire as the US launches an attack on Syria targeting different parts of the capital early Saturday, April 14, 2018.
"What decisions will be taken by the leadership of Russian Federation together with the representatives of Syria have yet to be determined", Lavrov said, but "there is no secret here".
An administration official confirms to CNN that the flights took place and the US and Israel are both concerned the cargo could potentially include weapons that could eventually be used to threaten Israel.
"I think Russians have no reason to seek friction with us, and we are not looking for friction with them", he said.
Israel has recently warned Iran against any moves to augment its military presence in Syria, where Iranian military advisers and militias have long provided critical support to Assad in his seven-year civil war against Sunni rebels. Russian Federation has left the door open to supplying Syria with advanced air defense measures-but has deliberately avoided giving details. But the question of providing S-300 air defense systems to Syria has not been settled yet, Lavrov told the media in Beijing on 22 April.
There are unconfirmed reports that suggest Syrian military forces have discovered two unexploded missiles and handed them over to their Russian peers for further examination.
"This is why we opposed so resolutely the Iran deal, because it gives Iran a clear path to a nuclear arsenal", Netanyahu said.
Russian Federation said the attacks removed all hurdles for providing Syria with the much better S-300.
He added that Israel will not allow an Iranian foothold in Syria, saying that this is the principle guiding Israel. Israel then retaliated by destroying Syrian anti-aircraft batteries.
While Israeli officials acknowledge that these strikes are carried out in general, Jerusalem rarely takes responsibility for specific attacks.