Russia is willing to help arrange a visit this week for experts from the international chemical weapons watchdog to the site of a suspected poison gas attack in Syria, a defence official has said.
Syrian opposition activists say 40 people died in Saturday night's chemical attack in the town of Douma, the last remaining rebel bastion near Damascus.
The opposition blamed president Bashar Assad's forces for the attack, accusations the government strongly denies.
Yevgeny Serberennikov, from the defence committee at the Federation Council, told the RIA Novosti news agency that Russia is anxious for the Organisation for the Prohibition of Chemical Weapons (OPCW) to "finally start carrying out the functions it was created for".
#Russia UN Envoy: Experts may immediately, tomorrow, fly to Damascus for investigation of the alleged #chemicalattack in #Douma. #Syria authorities, Russian troops will provide conditions to travel to the area of the alleged incident | https://t.co/RKBGBpI6bI | #DoumaProvocation pic.twitter.com/ZXX005HWTz
— Russian Embassy, UAE (@RusEmbassyUAE) April 10, 2018
Russia's offer comes as US president Donald Trump is threatening an imminent military strike against Syria.
Syrian war monitors say government forces and their allies are on alert and taking precautionary measures at military bases and posts across the country amid fears of a US attack.
Mr Trump vowed to respond "forcefully" to the apparent chemical weapons attack on civilians and warned that Russia or any other nation found to share responsibility will "pay a price".
The Britain-based Syrian Observatory for Human Rights said that as of Monday night, troops have been on a 72-hour alert and are fortifying their positions.
The Sound and Picture Organisation, an activist collective in eastern Syria, said Iranian fighters and members of Lebanon's Hezbollah group have evacuated their positions in the Boukamal area, near Iraq's border.