Russian Foreign Minister Sergei Lavrov said on Monday that Russian specialists had found no trace of a chemical attack on the Syrian rebel-held town of Douma, after allegations from the international community, AFP reported.
"Our military specialists have visited this place... and they did not find any trace of chlorine or any other chemical substance used against civilians," he said.
He also said that a strike on a Syrian airbase, that Damascus and Moscow have blamed on Israel, was a "very dangerous development".
"I hope at least that the US military and those of the countries participating in the coalition led by the United States understand that," Lavrov told a press conference.
The Russian army had earlier accused Israel of carrying out deadly missile strikes on a Syrian military airbase from Lebanon before dawn on Monday.
At least 14 fighters, including Iranians, were killed in the strike on the T-4 airbase, according to the monitoring organisation the Syrian Observatory for Human Rights.
Forces from regime allies Russia and Iran, as well as fighters from the Lebanese Hezbollah militia, are known to have a presence at the base, according to the observatory.
Washington and Paris denied any involvement.
Meanwhile, US President Donald Trump and French counterpart Emmanuel Macron have vowed a strong response to the suspected poison gas attack in the rebel outpost of Douma.
The UN Security Council was expected to discuss the crisis later on Monday.