Prime Minister Benjamin Netanyahu hinted during his recent meeting with Russian President Vladimir Putin that Israel would destroy Syrian S-300 missiles before they became fully operational, Maariv cited Middle Eastern diplomats saying Friday. The reported threat underlined how firmly Israel has sought to pressure Russia to cancel the deal, apparently with some success.

According to the report, during the meeting between the heads of state earlier this month in the Black Sea city of Sochi, Netanyahu called on Putin to cancel Russia’s transfer of the sophisticated anti-aircraft system to Syrian President Bashar Assad, and indicated that, should the delivery go ahead, Israel would strike the missiles before they became operational.

The report came the same day that American and German officials warned Russia not to send Assad the S-300 anti-aircraft missiles, and as Russian media indicated that Moscow was delaying delivery.

Officials present at the Netanyahu-Putin meeting “were shocked by the audacity Netanyahu displayed before a leader of a global power,” the Israeli paper reported.

Putin reportedly guaranteed that Assad wouldn’t transfer the S-300s to a third party, such as Hezbollah, and that should Israel strike such an arms convoy, Russia didn’t believe Syria would retaliate. Despite this, Netanyahu reportedly made clear that Israel was concerned over the deal in and of itself.

The Russian president was said to respond to Netanyahu saying that the deal had to go through, but hinted that Israel could prevent the transfer if it, or another entity, bought the missiles instead or “offered an alternative,” according to Maariv.

Israeli media had earlier reported that Netanyahu warned Putin of a descent into war should Russia make the delivery. Netanyahu said that if acquired by Assad, the S-300 “is likely to draw us into a response, and could send the region deteriorating into war,” Channel 2 reported two weeks ago, in the immediate aftermath of the meeting.

Russia has not yet delivered advanced S-300 missiles to Syria, despite rather vague Syrian indications to the contrary, two Russian media outlets reported on Friday.

The Russian business daily Vedomosti said that it was unclear whether or not the air-defense systems would be delivered this year, while the daily Kommersant reported that the S-300 missiles would only be delivered in the second quarter of 2014. According to Kommersant, the systems would need another six months of testing and training before they become operational.

The Lebanese newspaper al-Diyar reported Friday that Israel had succeeded in thwarting the missile deal by threatening to start an all-out war should Russia deliver the S-300s to the embattled Bashar Assad regime.

The report also claimed that Putin offered to compensate Assad with the delivery of other “effective and powerful weapons,” including modern aircraft and helicopters, to use against the Syrian rebels. According to al-Diyar, Putin also passed a message to Assad saying that the entry of Hezbollah into the Syrian conflict was not helpful. Hezbollah has a reported 5,000-7,000 gunmen now fighting with Assad’s forces.

Israeli sources said Thursday that Syria has only paid for one-third of the S-300 contract. They added that, even if the deal is eventually honored, it would take months for the S-300 batteries to be operational.

“It is not clear to me that the Russians are interested in transferring the weapons. Right now, it’s more of a threat,” said Ehud Ya’ari, Channel 2′s veteran, well-connected commentator.

In remarks erroneously attributed to Assad on Thursday, the Syrian president was said to have boasted in a TV interview that his country had received a first S-300 shipment from Russia, and to have asserted that “the rest of the load will arrive soon.” Israeli officials immediately said he was lying and bluffing.

What Assad actually said in the interview, on Hezbollah’s al-Manar television broadcast Thursday night, was that Russia had fulfilled some of its weapons contracts recently, but he was vague on whether this included the advanced air-defense systems. He said all contracts would be honored, and that Netanyahu’s visit to Russia two weeks ago, to plead that the S-300 deliveries not go ahead, would have no effect.

Russia’s declared intention to deliver the sophisticated systems, which can intercept fighter jets and cruise missiles, has created a tense standoff between Israel, Syria, and Russia, with Israel threatening to do “whatever it takes” to prevent the weapons being deployed, and Syria responding that it would retaliate in kind for any Israeli strike.

Aside from the unique strategic capacities that the S-300 air-defense missiles would afford Syria, putting planes taking off from central Israel and its main international airport within the missiles’ range, Jerusalem also fears that the system could fall into the hands of terror groups like Hezbollah.

Yoel Goldman and Stuart Winer contributed to this report.