Diplomats trying to secure a cease-fire for the civil war in Syria fell short early Friday in organizing a truce but agreed to try to work out details and implement a temporary "cessation of hostilities" in a week's time. The deal appeared to be the result of a compromise between the U.S., which had wanted an immediate cease-fire, and Russia. Although foreign ministers from the International Syria Support Group managed to seal an agreement to "accelerate and expand" deliveries of humanitarian aid to besieged Syrian communities beginning this week, their failure to agree on a cease-fire leaves the most critical step to resuming peace talks unresolved.It was not clear from their comments afterward if deep differences regarding the truce and which groups would be eligible for it could be overcome.Speaking for the group, U.S. Secretary of State John Kerry hailed the results as a significant accomplishment but noted that a cessation-of-hostilities agreement, if it can be achieved, would only be a "pause" in fighting and that more work would need to be done to turn it into a full-fledged cease-fire.He also allowed that the agreements made were "commitments on paper" only."The real test is whether or not all the parties honor those commitments and implement them," he told reporters after the nearly six-hour meeting at a Munich hotel, which ran into the early hours of Friday.While humanitarian access to be discussed by a working group on Friday in Geneva is key to relieving the suffering of millions of Syrians in the short term, a durable and lasting cease-fire will be required if stalled negotiations between the Assad regime and the opposition are to resume on or before a U.N.-set target date of Feb. 25. The talks broke down last month before they really started, due largely to gains by Assad's military with the heavy backing of Russian airstrikes.Kerry and Russian Foreign Minister Sergey Lavrov said the U.S. and Russia would co-chair both the working group on humanitarian aid as well as a task force that will try to deal with the "modalities" of the temporary truce. That task force will include members of the military along with representatives from countries that are supporting various armed groups in Syria. The Syrian regime and the opposition would both have to agree to the details.Russia had proposed the March 1 ceasefire date, which the U.S. and others saw as a ploy to give Moscow and the Syrian army three more weeks to try to crush Western- and Arab-backed opposition. The U.S. countered with demands for an immediate stop to the fighting.Despite apparent concessions on potential timing of the truce and the agreement to set up the task force, the U.S., Russia and others remain far apart on which groups should be eligible for it. The new task force will take up a job that was supposed to have been settled months ago. At the moment, only two groups the Daesh and the al-Qaida-affiliated al-Nusra Front are ineligible because they are identified as terrorist organizations by the United Nations.Russia, Syria and Iran argue that other groups, notably some supported by Turkey, Saudi Arabia and other Arab states, should not be eligible for the cease-fire, and there was no sign Friday that those differences had been resolved.Lavrov said the Russian air campaign in support of Assad's military would continue against terrorist groups and denied persistent reports that the Russian strikes have hit civilian areas, notably around opposition-held Aleppo, where heavy fighting has been raging for the past week.Among the issues the task force is charged with sorting out are delineating territories held by the Daesh, al-Nusra and other militant groups, ensuring the compliance of eligible parties and referring violations of the truce for appropriate action, including exclusion from the arrangement.Asked Friday to comment on the Munich talks, Salem Meslet, the spokesman for the Syrian opposition coalition known as the High Negotiations Commitee, said, "We must see action on the ground in Syria."Five years of conflict have killed more than a quarter-million people, created Europe's biggest refugee crisis since World War II and allowed the Daesh to carve out its own territory across parts of Syria and neighboring Iraq.Overall, the United Nations says almost half a million people are besieged in Syria. Since the beginning of 2015, Syria's government had approved just 13 inter-agency aid convoys, out of 113 requested, the U.N. reported last month.As Kerry met with the Syria group in Munich, U.S. Defense Secretary Ash Carter was in Brussels to rally fresh support for the fight against Daesh in largely the same territory.Carter said defense ministers from more than two dozen countries gave a "broad endorsement" of a refined U.S. plan for defeating the Daesh. After a meeting at NATO headquarters, Carter told reporters that nearly all participants either promised new military commitments or said their governments would consider new contributions. He predicted "tangible gains" in Iraq and Syria by March."We will all look back after victory and remember who participated in the fight," he said, appealing to coalition partners to expand and deepen their military contributions.NATO Secretary-General Jens Stoltenberg said the alliance agreed Thursday to deploy NATO airborne command and control aircraft in order to free up similar U.S. aircraft for the air campaign in Syria and Iraq.