In this image made from amateur video, released by the Shams News Network, people march and chant in Arabic in a village near Hama. -AP Photo

WASHINGTON: Syrian dissidents on Tuesday urged US President Barack Obama to call on Syrian leader Bashar al-Assad to quit power immediately and to press for UN sanctions against Syria over its deadly crackdown on protests.

Radwan Ziadeh said he and other dissidents presented their demands to Secretary of State Hillary Clinton in what the State Department said was the first time the US chief diplomat had met with Syrian opposition leaders.

Ziadeh, the director of the Syrian Center for political and strategic studies, said they need Obama “to address the Syrian people and ask President Bashar al-Assad to step down immediately.”

Mohammad Alabdalla, another Washington-based Syrian opposition activist, meanwhile told reporters after more than an hour of talks with Clinton that a US call for Assad to quit power would bring more protesters to Syria's streets.

Listing other demands, Ziadeh said “we need actually the US to lead at the Security Council to get more sanctions at the UN level, also to refer the crimes against humanity committed in Syria to the international criminal court.”

The United States and the European Union have imposed sanctions on Assad and other members of the Syrian regime but the UN Security Council has failed to even issue a condemnation of the deadly crackdown against demonstrators.

The 15-nation council remains divided over how to react to the Syria bloodshed, with Western nations demanding tough action and both China and Russia threatening to veto any formal resolution.

Clinton said last month that Assad had “lost legitimacy” after loyalists attacked the US and French embassies for alleged meddling in internal affairs, but administration officials have stopped short of calling on him to step down.

When asked why Washington was reluctant to call on the Syrian leader to quit power, Ziadeh said administration officials feared the Assad regime would try to fan sectarian flames and spark a civil war.

But “we addressed this concern” and showed that groups of different backgrounds, including Christians, were involved in the protest movement, he said.

“This is actually the great example about the unity of the Syrian people against the sectarian investment that the regime is investing in Syria,” Ziadeh told reporters.