BEIRUT: The hours ahead of a dawn deadline Thursday for Syria to fulfill its promise to observe a U.N-backed cease-fire were marked by pessimism that the fragile peace plan would end the government crackdown on dissidents that has seen more than 9,000 people killed.

New conditions that Syrian forces “remain on standby” generated skepticism from Western nations who suggested a cease-fire would not go beyond a temporary halt to hostilities and demanded the regime withdraw its troops from towns and cities.

International peace envoy Kofi Annan, who brokered the deal, said Wednesday he had received a written pledge from Damascus that regime forces would halt operations, provided they did not come under attack.

An unidentified Syrian Defense Ministry official, quoted by Syrian state television, meanwhile, said the army would indeed halt operations Thursday morning, but reserved the right to carry out “any assault” on what it described as armed groups.

The decision was taken after regime forces “completed successful operations in combating the criminal acts of the armed terrorist groups and enforced the state’s rule over its territory,” the official said, adding that armed forces would remain “on standby to retaliate against any attack by armed terrorist groups.”

It made no mention of withdrawing troops from urban areas – something that was previously agreed to begin Tuesday.The U.S. envoy to the United Nations, Susan Rice, said Tuesday’s broken promise meant Damascus’ pledge had “little if any credibility.”

Syria’s promise to Annan “is not and cannot in our judgment be construed as compliance” with the U.N.-backed peace plan, Rice told reporters.

“Fighting is still raging as we speak, reflecting what has been an intensification of the violence the Syrian government has pursued since April 1 when it committed to cease all hostile action,” Rice said. “Its commitments therefore have little, if any, credibility ... given that track record.”

Developments earlier in the day did not bode well either.

Even as the cease-fire pledge was being broadcast, activists were reporting more tanks moving into a major city. Activist groups said at least 14 civilians were killed in a bombardment of rebel neighborhoods in central Homs and other protest hubs. In Rastan, north of Homs, the Britain-based Syrian Observatory for Human Rights reported heavy shelling during the afternoon as troops clashed with rebels on its outskirts.

Armed opposition, who lack a coordinated command structure and means of communication, previously said they would stop shooting if Syrian forces pull back and observe the truce as promised..

“Annan, this is your cease-fire,” ran the sarcastic voice-over on an activist video that showed a shopping mall engulfed in flames after it was hit in a bombardment of the Juret al-Shayah district of Homs. Sniper fire cracked out in the background.

The rebel Free Syrian Army, meanwhile, warned it would resume attacks if the regime offensive did not stop.

“If [the regime] does not stop shelling and not withdraw tanks, we will intensify our military operations and launch attacks,” rebel spokesman Col. Kassem Saadeddine told AFP.

Speaking in Tehran, an optimistic Annan said he expected the situation to be “much improved” by Thursday’s cease-fire deadline if both sides respected his six-point peace plan.

Referring to “further clarifications” over how Damascus would implement its side of the plan, he described the answers as “positive,” adding that “governments with influence” had also been approached to ensure all sides respect the cease-fire.

Speaking at a joint news conference with Iranian Foreign Minister Ali Akbar Salehi, he urged Iran – Syria’s strongest ally – to help resolve the violence and warned of “unimaginable consequences” if it worsened further.

Salehi said Syrians should be able to have free elections contested by political parties but reiterated Iran’s opposition to any outside interference in Syria’s affairs.

Damascus’ other sympathizers on the U.N. Security Council, Beijing and Moscow, urged Syria to abide by the peace plan.

“China once again calls on the Syrian government to respond to the six-point proposal,” Foreign Ministry spokesman Liu Weimin said.

“At the same time, the Syrian opposition should also immediately stop fire and take practical measures to implement [the plan],” Liu told reporters.

Russian Foreign Minister Sergei Lavrov criticized the Syrian authorities for not heeding the peace plan more swiftly, saying “their action could have been more active [and] more decisive.”

German Foreign Minister Guido Westerwelle pressed Russia to distance itself further from Assad’s violence.

“Russia has to make clear that it does not want to have anything to do with these acts of violence and this repression,” Westerwelle said on the sidelines of a two-day meeting of Group of Eight ministers in Washington.

He called on the G-8 to send a “signal of unity and resolve” to Assad, and deplored the renewed bloodshed Wednesday. “Unfortunately, the violence continues,” he said.

Annan is to brief the U.N. Security Council by video link from Geneva Thursday, in what diplomats said would be “key” to the world body’s next steps.

Turkey’s Foreign Minister Ahmet Davutoglu also said he would discuss the Syria crisis with counterparts from the G-8 nations Wednesday evening, via a video conference call.

Ankara has urged the Security Council to adopt a resolution that would protect the Syrian people, saying Damascus had not kept its troop withdrawal pledge and had increased the violence.

The main opposition group, the Syrian National Council, has also urged that a return to the United Nations, an enforced arms embargo and sanctions must follow if the cease-fire fails.

“The chances that by tomorrow the regime will implement or abide by the cease-fire are weak, as we all know,” Syrian National Council spokeswoman Basma Kodmani said Wednesday.

“We would like to see a unanimous decision by members of the Security Council that sends an ultimatum to the regime with a deadline that is not too far down the road that says on such and such a date enforcement measures will intervene,” she said.

U.N. action would need the support of Russia and China, which have blocked previous Security Council draft resolutions on Syria, citing concerns about a Libya-style intervention that would breach Syrian sovereignty.

Syria’s Gulf opponents Saudi Arabia and Qatar have voiced calls to arm opposition rebel forces – a move Annan has described as “disastrous.”

Late Wednesday, Saudi Defense Minister Prince Salman bin Abdul-Aziz met with U.S. Defense Secretary Leon Panetta at the Pentagon for talks focused on the crisis in Syria. Pentagon officials expressed mutual concern over developments but would not confirm whether talks touched on the possibility of arming rebels.

Annan said his plan must be given a chance to work: “If everyone respects it, I think by 6 in the morning Thursday we shall see improved conditions on the ground,” he said.