International pressure is mounting on Syrian leader Bashar Assad, as diplomats from about 80 nations gather in Tunisia to discuss the crisis. NBC's Richard Engel reports.
Updated at 8:21 a.m. ET: LONDON -- Secretary of State Hillary Clinton suggested that Syria's opposition will ultimately arm itself and said she would bet against President Bashar Assad staying in power.
Her comments came ahead of a meeting of Western and Arab nations on Friday that was expected to demand that Syria implement an immediate cease-fire to allow aid in for desperate civilians in bombarded cities such as Homs amid an 11-month-old revolt.
Speaking directly to Russia and China, which have blocked U.N. Security Council resolutions designed to end the violence in Syria, Clinton said Thursday that the government's "brutality" against its own people was unsustainable in the Internet age.
"The strategy followed by the Syrians and their allies is one that can't stand the test of legitimacy or even brutality for any length of time," Clinton told reporters in London.
"There will be increasingly capable opposition forces. They will from somewhere, somehow, find the means to defend themselves as well as begin offensive measures," she added.
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"It is clear to me there will be a breaking point," Clinton said. "I wish it would be sooner, so that more lives would be saved, than later, but I have absolutely no doubt there will be such a breaking point."
Western and Arab foreign ministers were due to meet in Tunis on Friday.
While speaking to a group in London on Thursday, US Secretary of State Hillary Clinton discusses the violent situation in Syria and the future of President Bashar al-Assad.
The "Friends of Syria" meeting, that Clinton will attend, will call on Syrian forces to stop firing to give international aid groups access to areas worst hit by the violence which are running out of medicine and food, according to a draft declaration obtained by Reuters.
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The draft also "recognized the Syrian National Council as a legitimate representative of Syrians seeking peaceful democratic change," a phrase which appeared to fall short of full endorsement of the most prominent group opposed to Assad.
About 70 nations, including the United States, Turkey, and European and Arab countries that want Assad to step down, will take part in the talks, but Russia and China, which have jointly vetoed two U.N. Security Council resolutions on Syria, say they will stay away.
U.S. officials avoided answering questions on whether the group may discuss the possibility of arming the opposition, something that some nations favor and that the United States, in a change in emphasis, on Tuesday suggested could become an alternative.
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Alexei Pushkov, a Russian lawmaker, said Friday after meeting Assad that the Syrian president sounded confident and demonstrated no sign he would he step aside. Pushkov warned that arming the Syrian opposition would fuel civil war.
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The Syrian military pounded rebel-held Sunni Muslim districts of the besieged city of Homs for the 20th day on Thursday, despite international protest over the previous day's death toll of more than 80, including two Western journalists, activists said.
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Overnight, at least two people were killed as Syrian troops resumed the shelling of Homs, activists said.
More than 5,400 people have been killed in the nearly year-old uprising.
The draft conclusion of the "Friends of Syria" meeting also calls on Damascus "immediately to cease all violence" and pledges to deliver humanitarian supplies within 48 hours if Syria "stopped its assault on civilian areas and permitted access."
The group will also commit to enforce sanctions aimed at pressuring Syria authorities to halt violence, including travel bans, asset freezes, a halt to purchase of Syrian oil, ceasing infrastructure investment and financial services relating to Syria, reducing diplomatic ties and preventing arms shipments to the Syrian government.
After the death of two more journalists, Marie Colvin and Remi Ochlik, the city of Homs remains under siege and civilians have few medical supplies. NBC's Richard Engel reports.
If Assad fails to comply within 72 hours, a senior administration official in Washington said repercussions from the Tunis group might include new steps to plug the gap in sanctions Syria has tried to evade, including efforts to move money through Asia, Russia and Eastern Europe.
Another possibility, the official said, would be broadening an arms embargo already enforced by the United States, the European Union and Turkey, and being more rigorous in forcing the revocation of insurance for any ships that might carry weapons to Syria.
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The official said members of the "Friends of Syria" group were likely to pledge specific amounts of aid but did not expect them to consider arming the opposition. Arab diplomats have suggested, however, that formal or informal moves to arm the rebels may be discussed.
"One of the things you are going to see coming out of the meeting tomorrow are concrete proposals on how we, the international community, plan to support humanitarian organizations ... within days, meaning that the challenge is on the Syrian regime to respond to this," said a U.S. official.
U.S. officials are denouncing Syria for the killings of two foreign journalists, including American Marie Colvin, but the condemnations haven't stopped Syrian forces from carrying out new attacks on opposition strongholds. NBC's Richard Engel reports.
For more than a year the Syrian opposition has called for Assad, whose family has ruled Syria for four decades, to step down in the latest of the "Arab Spring" uprisings against authoritarian rulers in the Middle East.
The continued strife reflects both Assad's determination to remain in office as well as the major powers' inability to agree on a strategy on whether to try to ease, or force, him out.
Russia has repeatedly said it does not want a resolution to become a pretext for regime change, something it believes took place when the Security Council authorized the use of force to protect civilians in Libya and that ultimately helped drive former dictator Moammar Gadhafi from power.
Clinton, however, suggested Russia and China may not be able to sustain their opposition forever.
"The pressure will build on countries like Russia and China because world opinion is not going to stand idly by. Arab opinion is not going to be satisfied watching two nations, one for commercial reasons one for commercial and ideological reasons, bolstering a regime that is defying every rule of modern international norms," she added.
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Reuters and The Associated Press contributed to this report.