MOSCOW, May 19. /TASS/. A new air strike on the Syrian government troops by the US-led coalition is yet another proof of Washington’s non-constructive stance that undermines possibilities for anti-terrorism cooperation in the region, Russian officials said.

"The new US strike on government forces in Syria is a continuation of Washington’s non-constructive policy that started with the provocation in Idlib and the attack on the Syrian air base in Homs," said Leonid Slutsky, the head of the International Affairs Committee of State Duma, the lower chamber of the Russian parliament.

"Undoubtedly, such actions demonstrate the unpredictability of the American partners, which, of course, hampers the negotiation process on Syrian settlement, including on reaching agreements for the full resumption of the Russian-US memorandum on prevention of air incidents in Syria," he said.

"Such unilateral moves undermine the possibility of efficient cooperation and coordination in the fight against international terrorism in Syria," the head of the parliamentary committee said. "As Russia pays great effort to support the process of ceasefire in Syria, the US takes steps that weaken the forces combating the Islamic State and Nusrah Front (terrorist groups, outlawed in Russia) and de-facto plays into the hands of these terrorist groups."

Frants Klintshevich, the first deputy chair of the Defense and Security Committee of the upper chamber of the Russian parliament, said such actions may lead to a deadlock, when all chances for potential cooperation are eliminated.

The senator described the US-led coalition’s actions in Syria as "totally unrestrained."

"Apparently, the Syrian (conflict) has entered one of its tensest moments. Right now, important links may be severed and it will be extremely hard to restore them again," the Federation Council member was quoted as saying by his press service.

According to earlier reports, the international coalition led by the United States, conducted an air strike on a Syrian government convoy. The strike took place within a de-escalation zone northwest of the city of Al-Tanf, one of the four zones whose establishment was brokered by Russia, Iran and Turkey during the May 3-4 negotiations in Astana.

Under the deal, all military activity is banned in these zones, including air operations and sorties.