美俄围绕叙利亚战争恢复高级别面对面外交接洽

As U.S. Secretary of State John Kerry headed into another round of talks with his Russian counterpart, Sergei Lavrov, the American diplomats accompanying Kerry sought to downplay expectations of an imminent deal on a Syrian cease-fire.

“We can't guarantee in any way we are on the cusp of finality,” said one U.S. official.

But Kerry, who spoke by telephone with Russian Foreign Minister Lavrov at least four times Wednesday and Thursday, was optimistic enough to fly back to Switzerland for what is expected to be no more than a single day of negotiations.

The sticking points, for days, have been described by U.S. officials as “technical matters.” A key one, it has been revealed, involves ensuring “there will not be a siege of Aleppo,” according to a second State Department official who spoke to reporters aboard Kerry's plane. “It's not simply 'stop shooting,'” he added, explaining that overall the larger goal remains clearing the way for a transition stage to new leadership in Syria after a cease-fire holds.

There is considerable skepticism that a nationwide, sustainable cease-fire - the immediate goals as it has been repeatedly characterized by State Department officials - can hold for any period of time.

Syria is fractured after five years of war. There are numerous client forces of questionable allegiance and discipline pitted against each other, in addition to the so-called Islamic State group, which is beholden to no one.

Russia wants to see Syrian President Bashar al-Assad stay in power while moderate opposition forces and Turkey insist there can be no transition deal that retains him for any period of time.

The United States long-held stance is that the Syrian leader, for his brutal acts, cannot lead any future government.