WASHINGTON (AFP) - US lawmakers called on Sunday on President Barack Obama to provide intelligence and training to Syrian rebels through Arab states to speed the fall of the regime of President Bashar al-Assad.

Representative Mike Rogers, chairman of the House Intelligence Committee, said such a combination should also aim to leave a stabilising force in place in Syria after Assad's fall - without committing US ground forces.

"US leadership through intelligence and training" - in coordination with Arab League partners - "could be hugely helpful to bringing the regime down quicker, number one, and try to at least have a stabilising force exist after this happens," he said on CBS's Face The Nation.

The intensifying debate in the United States over what to do about Syria comes as Israel struck Syrian targets for the second time this week and follows US and other intelligence assessments that the Syrian regime has used chemical weapons.

Mr Obama, who had warned that use of chemical weapons would be a "game changer," has pressed for further evidence before taking action.

Mr Rogers, a Republican, said the situation in Syria was "deteriorating by the day" with thousands of foreign fighters flooding into the country on both sides of the civil war, creating an unstable mix.

They include Lebanon-based Hizbollah fighters who back the Assad regime and thousands of foreign fighters joining the al-Qaeda-linked al-Nusra Front on the rebel said, he said.

The ranking Democrat on the House Intelligence Committee, Dutch Ruppersberger, said the looming question was what happens after Assad falls, adding, "We can't be the sheriff for the whole world."

"So when we move and make the move to go in, we have to do it with a coalition, the Arab coalition and other countries in the area," he said.

"We have resources no other country has, and we have to make sure to use them. Some of the resources we have are the training of people fighting and the intelligence," he said.