The goal was to buttress Iran's defenses against Israel in Syria and to strengthen Syrian President Bashar al-Assad, as per sources.
Qatar, like Turkey, has backed the Syrian rebels and would not want to be seen to be selling them out. But it is also close to Iran as well as a strategic US partner.
Over the last several years, Iran has increasingly sought to target US forces in Iraq, and now increasingly in Syria.
The death toll in US airstrikes on pro-Iran installations in eastern Syria has risen to 19 fighters, a Syrian war monitoring group said on Saturday.
“It is very likely that we will witness the supply by Iran of radars and defense missiles, such as the 15 Khordad system, to reinforce Syria's air defenses,” Iranian state TV said.
The drone was attempting to conduct reconnaissance on an US patrol base when it was shot down.
Syrian President said that there will be talks with Turkey about ending the occupation of Syrian land and stopping the support for what he called terrorism.