Evidence implicates Assad in Syrian chemical weapons massacre, Hollande

France believes that President Bashar al-Assad's regime used chemical weapons against Syrian civilians in the much-publicised attack this week, President François Hollande said Sunday.

The scene after the alleged chemical weapons attack in Damsacus Reuters/Bassam Khabieh

There is "a body of evidence indicating that the 21 August attack was chemical in nature, and that everything led to the belief that the Syrian regime was responsible for this unspeakable act", Hollande said in a statement released by his office after he held telephone talks on the situation in Syria with Australian Prime Minister Kevin Rudd.

Hollande called for UN weapons inspectors to be given access to suspect sites "without delay and without any restrictions whatsoever".

Damascus had agreed the inspectors could investigate the charges, a statement by the Syrian foreign affairs ministry said on Sunday.

A separate statement issued after Hollande held phone talks with British Prime Minister David Cameron said the two leaders "unreservedly condemned the use of chemical weapons in Syria".

The presidency said Hollande and Cameron have agreed to hold talks soon on how to respond to the regime's "intolerable act", which it said France was determined "not to let... go unpunished."

The Syrian opposition accuses Assad's forces of killing more than 1,300 people Wednesday in chemical but the government denies the charge.

Doctors Without Borders said 355 people died this week of "neurotoxic" symptoms.

Urine, blood and hair samples collected in Damascus on Wednesday were being transported to various European capitals including Paris for testing, French newspaper Le Journal du Dimanche reported Sunday.

The results of previous samples taken from Syria in May led France to accuse the regime of using the nerve gas sarin.

US Defence Secretary Chuck Hagel said Sunday the US military was ready to take action against the Assad regime if ordered to by Barack Obama.

Hollande's government has been a keen supporter of the Syrian opposition.

Israeli President Shimon Peres called for an international effort to "take out" chemical weapons in Syria ahead of a meeting in Jerusalem with French Foreign Affairs Minister Laurent Fabius.

Fabius reiterated the French stance that "everything indicates a chemical massacre, and its very heavy responsibility falls on Bashar Al Assad".

"We don't understand the absence of a strong reaction by the international community after the facts have been proven," he said. "If the international community stays silent in front of such massacre, the people will wonder who or what can we trust."

Fabius is visiting Israel and the West Bank in what his office presented as a gesture of support for Israeli-Palestinian peace talks.