“Israel will not allow Iran, which calls for our destruction, to entrench on our border; we will do everything to prevent it from attaining nuclear weapons,” Netanyahu said.
He was speaking alongside Nikolai Patrushev, the head of Moscow’s powerful security council, whose visit followed weeks of simmering tensions between Tehran and Washington in the Gulf.
Israel has carried out repeated strikes to prevent Iranian forces becoming embedded in neighbouring Syria, where both Iran and Moscow back the government of President Bashar al-Assad.
The Israeli government has vowed never to let Iran obtain a nuclear weapon, believing Israel would be the target.
Iran insists its nuclear programme is entirely for civilian purposes.
Netanyahu has long campaigned against a 2015 nuclear agreement between Iran and world powers, from which the Trump administration unilaterally withdrew last year.
Patrushev did not directly mention the Islamic republic in his comments to the press.
“We pay great attention to Israel’s security,” he said.
“To resolve this issue in practice, it is necessary to bring peace and stability to the region, including on Syrian territory.”
Their meeting came a day after Netanyahu hosted US national security advisor John Bolton, who shares the Israeli premier’s tough stance on Iran.
Bolton is set to meet Patrushev on Tuesday along with their Israeli counterpart Meir Ben-Shabbat.
Tensions between Washington and Iran have flared after Iranian forces shot down a US drone Thursday, the latest in a series of incidents including attacks on tankers in sensitive Gulf waters that have raised fears of an unintended slide towards conflict.
Trump has tweeted that Washington would place “major additional sanctions on Iran on Monday”.
Russia on Monday denounced the new sanctions as “illegal”. Its President Vladimir Putin has warned of “disaster” if the US were to use force against Tehran.