MOSCOW - Russia will propose to the United Nations Security Council a draft resolution demanding an investigation into the alleged use of chemical weapons in Syria, Foreign Minister Sergei Lavrov said Tuesday.

In the resolution, Russia will ask the Organization for the Prohibition of Chemical Weapons (OPCW) to send experts to the location where the Syrian government forces reportedly used chemical weapons, Lavrov said at a press conference.

This document is necessary "to guarantee that the OPCW is implementing its obligations in accordance with the Chemical Weapons Convention and carrying out an investigation with an obligatory visit of the location," he said.

On Saturday, local activists said the Syrian government forces used chlorine gas in an attack in Douma district near Damascus, Syria's capital city, killing dozens of civilians.

The Syrian government denied the accusation and Russia also said the government forces did not use chemical weapons.

US President Donald Trump on Monday condemned the "heinous" attack and said he will decide within the next 24 to 48 hours whether to respond militarily.

Lavrov said that Moscow and Damascus demanded an "honest and transparent" investigation as the Syrian Red Crescent and Russian military experts had visited the location and found no trace of chemical agents.

The Syrian government and Russia invited OPCW experts to travel to Douma and Russia is ready to provide them with all the necessary safety guarantees, he said.

The diplomat added that those who do not allow experts to carry out on-site investigation under the pretext of lack of security guarantee will "show that they have no interest in establishing the truth."

According to Lavrov, Douma has been completely liberated from militants and is now controlled by the Syrian government forces, and Russian military personnel are also deployed there.