Mr Gerasimov cited what he called “reliable information” about militants he claimed were preparing to fake a government chemical attack against civilians.
He claimed the US would use this as a pretext to accuse Syrian government troops, and President Bashar Al Assad, of using prohibited chemical weapons and launch a missile strike on the Syrian capital.
Mr Gerasimov said: “In several districts of Eastern Ghouta, a crowd was assembled with women, children and old people, brought from other regions, who were to represent the victims of the chemical incident.
“In case there is a threat to the lives of our military, the Russian Armed Force will take retaliatory measures both over the missiles and carriers that will use them.”
Responding to the allegations, the US Department of Defence urged Russia to “stop creating distractions” and accused it of “enabling the Assad regime’s brutality”.
The comments come as Syrian President Bashar Al Assad’s regime, which is supported by Russia, continues to carry out airstrikes over the rebel-held enclave of Eastern Ghouta just outside Damascus.
The charity Medicin San Frontieres reported on Friday that 344 people have been wounded and 71 killed in East Ghouta every day for the last fortnight.
Two weeks ago the United Nations Security Council is demanded a ceasefire in Syria to allow allow almost 1,000 sick and wounded civilians to leave so they can get urgent medical treatment.
US Ambassador to the UN, Nikki Hailey yesterday warned it was ready to act.
She said: “It is not the path we prefer, but it is a path we have demonstrated we will take, and we are prepared to take again.
“When the international community consistently fails to act, there are times when states are compelled to take their own action.”
Syria has been locked in a brutal civil war for the last seven years following a popular uprising against Assad.
However, Assad’s regime stubbornly clung to power, with the assistance of ally Russia, which has been targeting the rebels. The result is that Assad has regained the upper hand.
In addition, these rebel groups have also been fighting the Islamic State, of ISIS, which still occupies parts of Syria.
Effectively, the war has become a proxy conflict between Russia and the West – although Mr Gerasimov’s words will surely stoke already-heightened tensions still further.
Russian Foreign Minister Sergei Lavrov was today reported by the Reuters news agency as saying that establishing more deescalation zones in Syria was not a priority for now.
He told reporters that it was important to prevent violation of ceasefire agreements in eastern Ghouta, a situation which he planned to discuss with Turkish Foreign Minister Mevlut Cavusoglu during his visit to Moscow.
The Cold War, generally regarded as covering the period from 1948 until the break-up of the Soviet Union in 1991, has a period which was fraught with tension, but no actual direct conflicts between the two superpowers. Instead, they backed rivals in different parts of the world as each sought to win greater influence.
The Cuban Missile Crisis in 1961, whereby the Soviet Union agreed to withdraw nuclear missiles from Fidel Castro’s Cuba after a stand-off with US President John Kennedy, is generally regarded as the closest the two came to a catastrophic conflict.