U.S., European and Arab officials met in London to work out details of an ultimatum to Assad. Diplomats said it would demand immediate compliance or result in additional punitive measures, likely to include toughened sanctions. The ultimatum is to be presented at a major international conference on Syria set for Friday in Tunisia.  A draft of the document obtained by The Associated Press calls on "the Syrian government to implement an immediate cease-fire and to allow free and unimpeded access by the United Nations and humanitarian agencies to carry out a full assessment of needs in Homs and other areas."  Homs has been under a fierce government attack for nearly three weeks.  The draft, which is still subject to change, also demands "that humanitarian agencies be permitted to deliver vital relief goods and services to civilians affected by the violence." More than 5,400 people have been killed in the nearly year-old uprising.  Meanwhile, Tunisia's presidential spokesman, Adnan Mancer, told The Associated Press in an interview ahead of Friday's meeting that the North African country will propose a political solution to the Syrian crisis that includes the deployment of a peacekeeping force and Assad stepping down from power.  The political transition would be akin to what happened in Yemen, where president Ali Abdullah Saleh stepped down in favor of his deputy after widespread protests. The Arab League already has made similar calls on Assad.  Also on the eve of the meeting, the United Naitons announced that former secretary-general Kofi Annan would be the joint U.N.-Arab League envoy to Syria. His mandate will be to try to end the violence and arrange a political transition.  American officials accompanying U.S. Secretary of State Hillary Rodham Clinton to the Tunis meeting of the "Friends of Syria" said the group hoped to make clear to Assad that his regime has a moral obligation to end the shelling of civilian areas and allow assistance into the country. The burden is on Assad to respond to the demands of the international community, they said.  The officials spoke on condition of anonymity due to the sensitivity of the ongoing discussions over how the ultimatum will be presented at the Tunis conference.  Several nations have proposed creating protected corridors through which humanitarian relief could flow but it was not clear whether a consensus could be reached on the matter, as such a step almost certainly would require a military component.  More workable, officials said, would be a cease-fire such as the one proposed by the International Committee of the Red Cross, which is calling for a daily two-hour break in fighting to provide aid.  "Our priority is to facilitate the delivery of the humanitarian assistance, and we have some proposals on the table to prepare the best way to deliver this assistance as quickly as possible — if the regime would accept to open the country to (outside groups) or to the Red Cross," French Foreign Minister Alain Juppe said after the discussions.  Clinton met Thursday in London with foreign ministers and senior officials from about a dozen countries, including Britain, France, Germany, Jordan, Morocco, Qatar, Saudi Arabia, Turkey, Tunisia and the United Arab Emirates. More than 70 nations and international organizations are expected at the Tunis meeting.  "The efforts that we are undertaking with the international community … are intended to demonstrate the Assad regime's deepening isolation," Clinton told reporters. "Our immediate focus is on increasing the pressure. We have got to find ways of getting food, medicine and other humanitarian assistance into affected areas. This takes time and it takes a lot of diplomacy."  If Assad doesn't comply, "We think that the pressure will continue to build. … I think that the strategy followed by the Syrians and their allies is one that can't stand the test of legitimacy … for any length of time," Clinton said. "There will be increasingly capable opposition forces. They will from somewhere, somehow find the means to defend themselves as well as begin offensive measures."  White House spokesman Jay Carney, traveling to Florida with President Barack Obama on Air Force One, told reporters the administration still opposes military intervention but "obviously we'll have to evaluate this as time goes on."  Other nations agreed that a military solution would be a last resort.  "There is no military option at the moment on the table, and as I have said before, France could not envisage such an option without an international mandate. It's a clear and constant guideline," Juppe said.  "It is a deeply frustrating situation," British Foreign Secretary William Hague told BBC radio ahead of the talks. He said the Assad regime "has continued to act seemingly with impunity."  However, Hague said military intervention was very unlikely, as "the consequences of any outside intervention are much harder to foresee."  Russia and China, the two nations that blocked an earlier attempt at a U.N. Security Council resolution against Assad, reiterated their continued opposition Thursday to any foreign intervention in Syria.  Russia and China have vetoed two Security Council resolutions backing Arab League plans aimed at ending the conflict in Syria and condemning Assad's crackdown.  Russian Foreign Minister Sergey Lavrov's office said he called his Chinese counterpart on Thursday and they "reaffirmed the joint position of Russia and China."  Both countries support "a speedy end to any violence in Syria and the launch of inclusive dialogue between the authorities and the opposition without preconditions for a peaceful settlement that excludes foreign interference in Syrian affairs," the ministry said.  Tunisian spokesman Mancer also said his country was ready to take part in the peacekeeping force to back "a political solution because we totally oppose a foreign military intervention."  The Tunis conference will also explore ways to further isolate Assad and his inner circle as well as boost engagement with the Syrian opposition to help them prepare for an eventual democratic transition.  "I know there is huge pressure, rightly, on everyone in the world, on the United Nations, on the United States, on Great Britain, on the Arab League, to do more to try to stop this butchery and this murder," British Prime Minister David Cameron told reporters.  He said nations attending the Tunis talks must "work out what more we can do as an international community to back the opposition, to tighten the sanctions, to put pressure on that regime, to say to countries like Russia and China you must not go on blocking" U.N. resolutions that would put pressure on the Assad regime.
The United States, Europe and Arab nations are preparing to demand that Syrian President Bashar Assad agree within days to a cease-fire.