On Tuesday, diplomats confirmed the UN Security Council intended to vote on the investigation into the Syria attack on Wednesday, just hours after Britain, France and the United States presented a new UN draft resolution demanding the probe.
The new measure would require "full cooperation with the investigation" into the apparent attack that took place in the rebel-held town of Khan Sheikhun, British Ambassador Matthew Rycroft said on Twitter.
Last week, the Security Council discussed three separate draft texts but failed to agree on a way forward, leading to no votes on any of the measures.
France, Britain and the United States pushed for a tough investigation and demanded that Syria provide information on its military operations, but that proposed draft faced the likelihood of a veto from Russia.
"We cannot give up and we must try, in good faith, the best we can, to have a text condemning the attack, asking for a thorough investigation," French Ambassador Francois Delattre told reporters.
Delattre said France was now looking for "a good text and a good vote."
A senior council diplomat said he expected a vote on the revised draft in the coming days.
France, Britain and the United States have accused President Bashar al-Assad's forces of carrying out the attack that killed at least 87 civilians, including 31 children.
"It's very important that there is a full investigation so that everybody knows, everybody knows, so that the entire world knows how these horrible chemical attacks occurred and where they come from," said Delattre.
As the council debated its response on Thursday, the United States fired cruise missiles at a Syrian airbase that the US says was used to launch the chemical attack.
France hopes that the US military action and Washington's demand that Assad be barred from power, as part of a peace deal that will open up a new opportunity for a solution to the conflict.
Russian President Vladimir Putin earlier called for a thorough investigation by the Organisation for the Prohibition of Chemical Weapons [OPCW] and suggested that Assad was the target of false accusations.
Meanwhile, Turkey's health minister confirmed that post-mortem tests on the victims showed that the deadly nerve agent sarin had been used in the April 4 attack.