President Bashar al-Assad has vowed to work to make a success of envoy Kofi Annan's peace plan, state news agency SANA said, as Arab leaders on Thursday urged dialogue to end Syria's crackdown on dissent.

On the ground, monitors reported that 36 people were killed in violence across the country, while the United Nations said at least one million Syrians were in dire need of need humanitarian assistance,

Assad stressed the UN-Arab League envoy's plan would succeed only if "terrorist acts" backed by foreign powers stopped across the country, SANA reported.

"President Assad... has informed Annan that Syria approves the plan (the envoy) submitted but had made remarks about it," and pledged he would "spare no effort" to make it work, the agency said.

Assad's remarks were made in a message to the world's emerging powers meeting Thursday in New Delhi.

Annan's plan calls for a halt to violence, daily two-hour humanitarian truce, media access to areas of fighting, for political dialogue, the right to demonstrate and the release of detainees.

The United States was unimpressed by Assad's comments.

"We've seen absolutely nothing on the ground that indicates that they're adhering to its calls for Syrian artillery and heavy weaponry to go back to barracks and for a ceasefire," said State Department spokesman Mark Toner.

"We want to see an end to the violence as soon as possible so that we can get humanitarian assistance in to the beleaguered Syrian people," he said.

His remarks came as a UN spokesman said at the end of a Syrian government-led assessment mission to the country that at least one million Syrians needed humanitarian assistance.

Eight UN experts and three from the Organisation of Islamic Cooperation (OIC) took part in the tour which ended on Monday.

"The joint analysis of the OIC and UN indicates that at least one million Syrians are in need of humanitarian assistance," said deputy UN spokesman Eduardo del Buey.

At a summit in Baghdad, Arab leaders approved a resolution calling for an end to Syria's brutal crackdown, for the opposition to unite and for parties to the conflict to launch a "serious national dialogue."

A warning from Iraqi Prime Minister Nuri al-Maliki against arming the parties to the conflict highlighted the split in the 22-member Arab League, from which Syria has been suspended because of the violence.

While hardliners Qatar and Saudi Arabia have called for Assad to step down and for rebels opposing his regime to be supplied with weapons, others including Iraq have been pushing for a political reconciliation.

"Based on our experience in Iraq, the option to arm either side of the conflict will lead to a regional and international proxy war in Syria," Maliki warned in his speech to Arab leaders.

Also in the Iraqi capital, UN chief Ban Ki-moon urged the Syrian regime to start implementing Annan's plan. "The world is waiting for commitments to be translated into action... There is no time to waste," he said.

The world's emerging powers, meanwhile, said at a summit in New Delhi that dialogue was the only answer to the crises in both Syria and Iran.

Leaders of BRICS -- Brazil, Russia, India, China and South Africa -- issued a pre-emptive warning against any military action by the West or Israel to end the unrest in Syria or the dispute over Iran's nuclear programme.

"We agreed that a lasting solution in Syria and Iran can only be found through dialogue," Indian Prime Minister Manmohan Singh said.

In violence across Syria on Thursday, at least 36 people, most of them civilians, were killed, monitors said.

The highest toll was in the central province of Homs where seven civilians, including two women, were killed as regime forces fought armed rebels, the Syrian Observatory for Human Rights reported.

Six soldiers, including two officers, and a rebel died in the clashes, it said.

A woman and a child were among five civilians who died as regime forces stormed villages near Maaret al-Numan in northwestern Idlib province, the Britain-based Observatory said. Three soldiers also died.

Reporters Without Borders, meanwhile, said two freelance journalists, including a Briton of Algerian origin, were shot dead by Syrian forces earlier this week on the border with Turkey.

In London, the Foreign Office said it was investigating the media watchdog's report that one of the journalists was a British national of Algerian origin.

The media in Iran, meanwhile, reported that up to 12 Iranians -- Shiite pilgrims and engineers -- who were kidnapped in Syria several months ago had been released.

Rebels have accused Iran of helping Syrian authorities in their crackdown.

Iran's supreme leader, Ayatollah Ali Khamenei, said on Thursday that the Islamic republic will defend the regime of its regional ally Syria due to its anti-Israeli stand.

"Iran will defend Syria because of its support for the anti-Zionist regime resistance," he said.