US: 'Syrian Regime Planned Attack For Days'

The United States has outlined the evidence it believes proves the Syrian regime was behind a chemical weapons attack that killed over 1,400 people.

US Secretary of State John Kerry said President Bashar al Assad's personnel were on the ground making preparations for a chemical assault for three days before the nerve gas atrocity in Damascus.

And he said intelligence shows that elements in Mr Assad's government were told to prepare by putting on gas masks.

Mr Kerry said the Syrian regime was determined to rid the capital's suburbs of the opposition and it was frustrated that it had not succeeded in doing so.

He claimed the rockets used in last week's attack came from regime-controlled areas and hit only opposition-controlled or contested neighbourhoods.

And he also said a senior regime official confirmed the weapons were used and was afraid the world would find out.

Mr Kerry was speaking as a US intelligence report was released which blamed Syria's government for the attack with "high confidence" and said it was "highly unlikely" the atrocity was plotted by rebels.

The report said 1,429 people were killed, including 426 children, and said the assessment was based on "multiple" streams of intelligence.

The report cited human and satellite intelligence that it said backed up publicly available videos and other evidence.

The intelligence gathered for the report included an intercepted communication by a senior official intimately familiar with the August 21 attack as well as other intelligence from people's accounts and intercepted messages, it said.

The Assad government has denied using chemical weapons, saying the assault was carried out by rebels.

And a Syrian foreign ministry statement dismissed the US intelligence report as "entirely fabricated".

It comes as US President Barack Obama is preparing for a possible military strike in response to the atrocity.

Mr Obama said he has not made a final decision on attacking Syria but was mulling a "narrow and limited" strike - which reports say would probably be carried out using Tomahawk cruise missiles.

The American leader said of the suspected gas assault: "This kind of attack is a challenge to the world", adding it threatens US allies like Israel, Turkey and Jordan.

Mr Kerry said any action would be a "tailored response" to punish Mr Assad for the "brutal and fragrant" attack.

Meanwhile, a team of United Nations inspectors has finished collecting samples from the site of the atrocity.

The team will leave the capital Damascus on Saturday and will then return to The Hague.

Samples collected from the attack are to be analysed in several laboratories in Europe.

A UN spokesman stressed that all available information, including lab analysis of the samples, had to be evaluated "before the mission can draw any conclusions about the incident".

The UN mandate is to determine if a chemical weapons attack took place.

Veto-holding members of the United Nations are at odds over a draft Security Council resolution that would authorise "all necessary force" in response to the alleged gas attack.

Mr Kerry insisted the US was not alone in its quest to punish the Syrian regime, citing the support of France, America's "oldest ally".

Key US ally Britain dropped out of the coalition planning military strikes following a parliamentary vote.

The UK's traditional role as America's most reliable military ally was called into question when David Cameron became the first British prime minister in history to be blocked by MPs over the prospect of military action.

A chastened-looking PM, struggling to make himself heard over calls of "resign" from the opposition benches, told them "I get it" as he abandoned hopes of joining any US strike on Syria.

America is mulling whether to strike Syria without UN backing despite some of the more hawkish figures in the US cautioning against military action.

Former president, George W Bush, told Fox News Mr Obama had a "tough choice to make" but would not be drawn on what he should do.

He added: "I was not a fan of Mr Assad. He's an ally of Iran and has made mischief."

Former defence secretary Donald Rumsfeld, who helped spearhead US invasions in Iraq and Afghanistan, said: "There really hasn’t been any indication from the administration as to what our national interest is with respect to this particular situation."

He said, if anything, the US should be more concerned with Iran.