JERUDONG, Brunei (AFP) - US forces are "ready to go" if called on to strike the Syrian regime, Defence Secretary Chuck Hagel told the BBC on Tuesday, saying evidence pointed to its use of chemical weapons.

The comments by Mr Hagel, who is on a tour of South-east Asia, will add to mounting speculation that the United States and European allies are poised to launch an assault on Syria over a deadly chemical weapons attack in its long-running battle against rebels.

The Pentagon chief said forces had been deployed as needed and President Barack Obama had reviewed military options presented by commanders.

"We are prepared. We have moved assets in place to be able to fulfil and comply with whatever option the president wishes to take," he said. "We are ready to go, like that."

Mr Hagel said in the interview that Washington would soon share evidence that it was the Syrian regime which unleashed chemical weapons last week on the outskirts of Damascus. "Syria used chemical weapons against its own people," Hagel said in the interview.

"Now, we'll have more information and more intelligence here very shortly to present. I think the Secretary (of State John Kerry) noted that yesterday," he said in Brunei, where he is attending a regional gathering of defence ministers.

After speaking to his British and French counterparts by phone earlier on Tuesday, Mr Hagel said US allies and most of the world believed President Bashar al-Assad's regime was behind the chemical attack.

"I think most of our allies, most of our partners, most of the international community that we've talked (to) - and we have reached out to many - have little doubt that the most base, human, international humanitarian standard was violated in using chemical weapons against their own people," he said.

He said there was no longer a question about who staged the assault, which the opposition says killed 1,300 people.

"I think the intelligence will conclude that it wasn't the rebels who used it, and there'll probably be pretty good intelligence to show ... that the Syria government was responsible," he said.

"The deeper we get into this, it seems to me it's clearer and clearer that the government of Syria was responsible."

Mr Hagel's comments reflected increasingly hawkish rhetoric from Mr Obama's administration, which had previously sought to avoid being drawn into the Syrian conflict.

But the administration's view has shifted, with officials saying the use of chemical weapons represents a dangerous precedent.