Israel signalled on Sunday that it would keep up military strikes across its frontier with Syria to prevent any encroachment by Iranian-allied forces, even as the United States and Russia try to build up a ceasefire in the area.
US President Donald Trump and Russian President Vladimir Putin on Saturday affirmed joint efforts to stabilise Syria as its civil war wanes, including with the expansion of a July 7 truce in the southwestern triangle bordering Israel and Jordan.
A US State Department official said Russia had agreed "to work with the Syrian regime to remove Iranian-backed forces a defined distance" from the Golan Heights frontier with Israel, which captured the plateau in the 1967 Middle East war.
Moscow did not immediately provide details on the deal.
Israel has been lobbying both big powers to deny Iran, Lebanon's Hezbollah and other Shia militias any permanent bases in Syria, and to keep them away from the Golan, as they gain ground while helping Damascus beat back Sunni-led rebels.
In televised remarks opening Israel's weekly cabinet meeting on Sunday, Prime Minister Benjamin Netanyahu did not speak about the new US-Russian arrangement for Syria.
His regional cooperation minister, Tzachi Hanegbi, sounded circumspect about the deal, telling reporters that it "does not meet Israel's unequivocal demand the there will not be developments that bring the forces of Hezbollah or Iran to the Israel-Syria border in the north".
"There's reflection here of the understanding that Israel has set red lines, and will stand firm on this," Hanegbi said.
That was an allusion to Israeli military strikes in Syria, carried out against suspected Hezbollah or Iranian arms depots or in retaliation for attacks from the Syrian-held Golan.
In the latest incident, the Israeli military said it shot down a spy drone on Saturday as it overflew the Golan. Israeli Defence Minister Avigdor Lieberman blamed the drone on the Syrian government. Damascus did not immediately respond.
Repeating Israel's warnings to Iran and Hezbollah, Lieberman said:
We will not allow the Shia axis to establish Syria as its forefront base
Russia, which has a long-term military garrison in Syria, has said it wants foreign forces to quit the country eventually.
The US State Department official, who briefed reporters on condition of anonymity on Saturday, said that goal could be served by Russia's pledge to remove Iranian-linked fighters from the truce zone in southwestern Syria.
"If this works, this is an auspicious signal, would be an auspicious signal, that our policy objective – the objective that I think so many of us share, of getting these guys out of Syria ultimately – that there's a path in that direction," the official said.