Smoke rises after the Syrian army's shelling targeted the Douma district in Eastern Ghouta countryside of Damascus, Syria, on April 7, 2018. (Xinhua/Ammar Safarjalani)

UNITED NATIONS, April 13 (Xinhua) -- UN Secretary-General Antonio Guterres on Friday warned of the danger of a full-blown military escalation in Syria.

"Increasing tensions and the inability to reach a compromise in the establishment of an accountability mechanism (for chemical weapons use in Syria) threaten to lead to a full-blown military escalation," Guterres told the Security Council.

"In my contacts with you -- especially with the permanent members of the Security Council -- I have been reiterating my deep concerns about the risks of the current impasse and stressed the need to avoid the situation spiralling out of control. This is exactly the risk we face today -- that things spiral out of control," said the UN chief.

"It is our common duty to stop it."

He said Syria represents the most serious threat to international peace and security today.

"In Syria, we see confrontations and proxy wars involving several national armies, a number of armed opposition groups, many national and international militia, foreign fighters from everywhere in the world, and various terrorist organizations," he told the Security Council, which was convening at the request of Russia.

"From the beginning, we have witnessed systematic violations of international humanitarian law, international human rights law, and international law tout court -- in utter disregard of the letter and spirit of the United Nations Charter."

He noted that Security Council Resolution 2401 that demands a cease-fire across Syria to allow humanitarian assistance was not implemented.

The continued reports of chemical weapons use in Syria are outrageous, he said. He deplored the fact that the Security Council could not reach agreement on a dedicated mechanism for attributing accountability.

But he said there is no military solution to the conflict. "The solution must be political through the Geneva intra-Syrian talks."