PARIS (AP) -- U.S. Secretary of State Hillary Rodham Clinton called Thursday for the U.N. Security Council to adopt a global arms embargo and other tough measures against Syria to reinforce existing Western embargoes if the country fails to abide by a cease-fire designed to end 13 months of bloodshed.
Clinton stopped short of calling for outside military intervention in Syria -- something there is little to no foreign appetite for -- and acknowledged Russia and China would likely veto any U.N. measure. But she insisted it was time to impose more consequential measures on Syrian President Bashar Assad's regime.
"We have to keep Assad off balance by leaving options on the table," she said at a Paris meeting of top Western and Arab diplomats from the so-called "Friends of Syria" group.
Clinton's address made it clear that the U.S. has little faith in the success of special envoy Kofi Annan's six-point peace plan. But although U.S. policy has amounted to an acknowledgment that Assad is unlikely to be ousted, the U.N. resolution Clinton seeks could strengthen rebels fighting the Syrian strongman.
"We need to start moving very vigorously in the Security Council for a Chapter 7 sanctions resolution, including travel, financial sanctions, an arms embargo, and the pressure that that will give us on the regime to push for compliance with Kofi Annan's six-point plan," Clinton said.
Moscow and Beijing have already twice shielded Syria from U.N. sanctions over its crackdown on a popular uprising inspired by the Arab Spring movements in other parts of the Middle East and North Africa.
Clinton said she laid out the case for U.N. Security Council action earlier Thursday to Russian Foreign Minister Sergey Lavrov, whom she said "has recognized that we are not in a static situation but a deteriorating one."
Over the past 13 months, the Syrian government's crackdown is said to have killed more than 9,000 people. At the Paris meeting of 16 top diplomats, French Foreign Minister Alain Juppe said the Friends of Syria group believes Annan's plan is the "last chance" for Syria to avoid civil war.
Earlier Thursday, U.N. Secretary-General Ban Ki-moon said Syria was not honoring the Annan cease-fire, which took effect last week, and that violence was escalating. Syrian activists said regime forces took control of a southern town and shot at activists in another soon after international observers left.
Ban recommended that the Security Council quickly approve a 300-strong U.N. observer mission to Syria, a number larger than what was originally envisioned. But he said will review ground developments before deciding when to deploy the mission.
Ban said the mission's success depends on Syria's full cooperation, and he demanded that Assad's government ensure that the observers have unrestricted freedom of movement, unfettered access to the Syrian people, and the use of helicopters and fixed-wing aircraft for their mobility.
He said the U.N. and Syria signed "a preliminary protocol" in Damascus on Thursday but are still discussing the use of aircraft the nationalities of the observers. Ban said Syria's U.N. ambassador Bashar Ja'afari had assured him "there will be full support, including air mobility."
At U.N. headquarters in New York, Ban called the situation in Syria "highly precarious," and said attacks are on the rise including "shelling of civilian areas, grave abuses by government forces and attacks by armed groups."
U.S. Ambassador Susan Rice, the current Security Council president, said council members would have to send Ban's recommendation for the expanded observer mission back to their capitals. Russia's U.N. Ambassador Vitaly Churkin said Moscow supports the expanded mission.
France and the United States and others have repeatedly called for Assad to step aside. But the Obama administration's policy now reflects a consensus that Assad -- with support from the military -- has a strong hold on power and only an outside military strike could quickly oust him.
The evolving U.S. position comes amid signs that rebel forces are poorly armed and disorganized, efforts to pay them by Arab Gulf states are failing, and sectarian divisions loom in Syria.
During testimony before the U.S. Congress on Thursday, U.S. Defense Secretary Leon Panetta and Army Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, outlined the steps the U.S. and other countries are taking to pressure Syria, including $25 million in emergency humanitarian assistance.
Dempsey said if called upon, the military would be ready to act and the services are working on ways to try to halt the violence. But both he and Panetta set a high threshold for U.S. military involvement in a war in the Middle East after decade-plus conflicts in Iraq and Afghanistan.
When pressed on the issue, Panetta said, "At this point in time ...a decision is that we will not have any boots on the ground and that we will not act unilaterally in that part of the world."
Much could depend on the role of Russia, which considers Syria a critical ally that it is loathe to lose. In recent weeks, Russian leaders have sharpened their criticism of Assad, but have not given way on allowing any U.N. sanctions against Damascus.
Marina Ottaway, an analyst at the Carnegie Endowment for International Peace, a Washington think tank, said that a failure of the cease-fire and the Annan plan would likely increase pressure on Russia to give some ground and allow limited action against Syria.
"What is left to do is to go back to the Security Council and try to get some sort of resolution through that provides some cover for the countries that want to provide weapons," she said.
"I don't think we are going to get Russia or China to agree to foreign intervention, but I think the present situation is going to make it very difficult for Russia to continue saying we have to try to diplomacy, because the regime has shown once again that it has no intention of moving," she added.
At the Paris meeting, Foreign Minister Saad-Eddine El-Othmani of Morocco, whose country holds a Security Council seat, spoke in optimistic terms about Russia's position, saying he was "convinced that the Russians can participate in an effort to stop the violence.
"I was in Moscow yesterday, and spoke a long time with (Russian foreign minister) Lavrov," El-Othmani said. "They have criticized the Friends of Syria -- that's his right -- but the main thing is that he's open, he supports the Annan plan and supports the observers' mission."
Only a small number of international observers are currently in Syria. On Thursday, the observers visited the southern province of Daraa, where activists said anti-regime protesters gathered around them in the village of Khirbet Ghazaleh. The state-run news agency confirmed the observers went to Daraa.
An amateur video posted online by activists showed at least two of the observers, including the team's head Col. Ahmed Himiche, standing outside a U.N. vehicle as dozens of people chanted "death is better than humiliation" and "the people want to topple the regime."
Troops also stormed and took control of the southern town of Busra al-Harir, which regime forces have been attacking for about a month, the Local Coordination Committees activist group said.
Adel al-Omari, an activist based near Busra al-Harir, said the whole town fell in the hand of regime forces Wednesday night after army defectors withdrew from the area.
"Forty percent of Busra al-Harir's homes are destroyed because of the shelling," he said, adding that regime forces are detaining many in the town. "There is a lack of medical products, and regime forces have taken over makeshift hospitals."
Al-Omari said that as observers were visiting the village of Hirak, hundreds of protesters chanted for the downfall of Assad's regime. "Once the observers left, security forces started shooting to disperse the demonstration," al-Omari said, adding that at least three protesters were wounded.
The Local Coordination Committees said troops opened fire in the Mahata area in the southern city of Daraa, apparently to impose a curfew. It said at least 10 civilians were wounded in the shooting.
Bassem Mroue and Elizabeth A. Kennedy in Beirut, Edith Lederer in the United Nations, and John Heilprin in Geneva contributed to this report.