Barack Obama and his Secretary of State have renewed calls for strikes on Syria.

The US President has now won the backing of the Republican leader in the House of Representatives, ahead of a Congress vote next week on whether to take military action.

John Kerry says there's no chance of American boots on the ground in Syria.

Obama, Defense Secretary Chuck Hagel and Secretary of State John Kerry all addressed a Senate Panel yesterday.

John Kerry told the Senate Panel that he and some of Obama's other top supporters were present when the decision to put troops in Iraq was made - he said they never wanted to take another vote on 'faulty intelligence'.

But he insists something must be done: 

Secretary Kerry said again that the chemical attack in Syria was a red-line issue for the whole world.

John Kerry said it was wrong to claim that only President Obama had drawn a line on the use of chemical weapons.

Speaking after the hearing, US General Martin Dempsey has conceded that Russia could step up aid to the Assad regime if attacked, "There is some indication that they have assured the regime that if we destroy something they can replace it, but that's not a reason for me to hesitate to act. We know what the consequences, could be, probably would be if we do not act."

It came as the UN Secretary General warned that a strike without UN approval would be illegal.