UN Secretary-General Antonio Guterres warned Tuesday that the recent downings of a Syrian jet and of an Iranian-made drone could be "very dangerous" and lead to an escalation of the war in Syria.
Guterres also sought to downplay expectations of a breakthrough in the next round of UN-led peace talks on Syria starting on July 10.
"Indeed I am concerned and I hope that this will not lead to any escalation of the conflict that is already as dramatic as it is," Guterres told a news conference at UN headquarters.
A US warplane shot down an Iranian-made drone operated by pro-regime forces in southern Syria early Tuesday, in the latest incident in rising tensions between the two sides.
On Sunday, a US fighter jet downed a Syrian government warplane for the first time in the country's conflict just south of Raqa, sparking an angry reaction from regime ally Russia.
"I strongly hope that there will be a de-escalation of the situation because these kinds of incidents can be very dangerous in a conflict situation in which there are so many actors and in which the situation is so complex on the ground," said Guterres.
The United Nations is preparing to host in Geneva a new round of talks on ending the six-year war.
Guterres said that given the "complexity of the situation... I don't want to create false expectations about immediate results" from the upcoming round of negotiations