WASHINGTON (AFP) - Republican lawmakers stepped up calls for US action against Syria on Sunday in the face of growing evidence that it used chemical weapons against its population in a bitter civil war.
But wide differences remained over what should be done and whether President Barack Obama was correct in proceeding cautiously before declaring that the regime of President Bashar al-Assad has crossed a game-changing "red line."
"I think the options aren't huge, but some action needs to be taken," said Representative Mike Rogers, the Republican chairman of the House Intelligence Committee.
Speaking on ABC television's This Week, Mr Rogers cited classified information that he said "strengthens the case that in fact some small amount of chemical weapons have been used over the course of the last two years." "And the problem is, you know the president has laid down the line - and it can't be a dotted line. It can't be anything other than a red line," he added.
A US intelligence assessment earlier this week found that the Syrian regime was likely to have used chemical weapons against its civilian population, but the White House said Mr Obama wanted more proof.
Mr Obama has warned that Syria's use of chemical weapons would be a "game changer" that crosses a US "red line." The United States has provided non-lethal aid and political support to Syrian rebels, but so far has shied away from supplying weapons or other military assistance.
Certain influential Republicans, who have long called for US military aid to the Syrian opposition, warned that inaction now sends the wrong message to Iran about US seriousness on its nuclear weapons programme.
"If we keep this hands-off approach to Syria, this indecisive action toward Syria... we're going to start a war with Iran," Senator Lindsey Graham said on CBS's Face The Nation. "We need to get involved. And there's a growing consensus in the US Senate that the United States should get involved." But he acknowledged that "Syria is difficult," and action there would be risky.
Senator John McCain, another hawk on Syria, called for creating an "international force to go in and secure these stocks of chemical weapons and perhaps biological weapons."
"They cannot fall into the hands of the jihadists, otherwise we will end up seeing these weapons being used in other places in the Middle East," he said on NBC's Meet The Press.
Israel's ambassador to the United States, Michael Oren, said the United States was in high-level discussions with Israel and other countries in the Middle East "working out ways we can address this threat."
He warned, however, that military action against Syria's huge chemical weapons stockpile would be "a complex operation."
"Even under international law, if you strike a chemical weapons base and there is collateral damage to civilians it is as if you, the attacker, used chemical weapons," Mr Oren told Fox News Sunday.
"That's why Israel is not making, urging any action by the United States in Syria, because we understand the complexity of it and we share the concerns of the United States and our neighbors."
Democratic lawmakers and former policymakers said Obama was right to approach the Syrian problem carefully in light of past US mistakes in Iraq, where a flawed US intelligence assessment led to a US invasion.
"You know, we've had a little problem with going to the UN with the idea of weapons of mass destruction before. So we certainly want to finish the investigation," Representative Jan Schakowsky, a Democrat from Illinois, said on ABC's This Week.