The Iranian military is said to have established a compound at a site used by the Syrian army outside El-Kiswah, 14 km (8 miles) south of Damascus.
With so-called Islamic State (IS) suffering major defeats on the battlefield and losing its last strongholds, attention is increasingly turning to what comes next and the new map of power and influence in Syria.
With a significant number of IRGC fighting – and in some cases dying – in Syria, there has already been a significant presence in the country but the question is now whether they are preparing to remain in the long term.
The presence of Iranian forces in Syria has been reported for some time but the claim of a potentially more permanent Iranian base raises the possibility of military action by Israel which has repeatedly warned it will not tolerate such a development.
When asked whether Israel would use military force to stop such developments, Mr Netanyahu told the BBC: “You know, the more we’re prepared to stop it, the less likely we’ll have to resort to much greater things.