UNITED NATIONS - Israeli strikes that have crippled two Syrian airports are extremely worrying, said a UN spokesman on Thursday.

Reports of Israeli strikes on Aleppo and Damascus airports are extremely worrying, especially in light of the warnings and the concern of UN Secretary-General Antonio Guterres for an escalation of the tensions between Israelis and Palestinians, said Stephane Dujarric, Guterres' spokesman.

Guterres strongly condemns all violence in Syria and urges all parties to respect their obligations under international law, recalling that civilians and civilian infrastructure must be protected under international humanitarian law, said the spokesman.

"We're at a time where these heightened tensions, where any miscalculation could lead to broader violence in an already volatile region," he told a daily press briefing.

The fact that the two airports are not functioning will have a temporary halt on the UN Humanitarian Air Service, which operates out of both airports to service the Syrian humanitarian programs, he said.

Syria's SANA state news agency reported Thursday that Israeli missile strikes have put the international airports in Damascus and Aleppo out of service.