The United States outlined no change in its Syria policy as a target date for a political transition passed Monday, despite warning a few months ago that no progress would lead to a more muscular approach for ending the 51⁄2-year-old civil war. At a news conference in Washington, Secretary of State John Kerry said the US would press on with a multi-month effort to prod Syrian President Bashar Al-Assad and moderate opposition groups into a lasting truce and talks on a unity government. Kerry's tone was dramatically different from early May, when he issued an Aug. 1 ultimatum to Assad and his main backer Russia and warned of "repercussions." He said at the time, "Either something happens in these next few months, or they are asking for a very different track." But on Monday, the top American described a US strategy for Syria that is stuck where it started. "Almost all of the time from the moment of the announcement of the target date until today has been consumed by trying to get a cessation of hostilities in place that is meaningful," Kerry said. "And that is precisely what we are engaged in right now." Although it was never likely that the Obama administration would confront Assad directly, Kerry's comments three months ago implied a clear policy change would come. That could still be happening, but Kerry provided no such hint Monday. Instead, he seemed to share the blame for Syria's standstill, pointing to offensive operations by both Assad's government and the Nusra Front, for preventing a truce from sticking. Several Syrian opposition groups are embedded with Nusra, and Kerry said Washington had a responsibility to control them. Russia, he said, must restrain itself and Assad's government. "Now, my hope is that we can arrive at that," Kerry said, before issuing a new, if vaguer, suggestion of a potential US breaking point. "If we can't, nobody is going to sit around and allow this pretense to continue." The war has killed as many as a half-million people since 2011, contributed to a global migration crisis and created a vacuum that allowed Daesh to capture territory and emerge as a global terror concern. In that time, the US has issued various, unfulfilled threats of its own, from declaring Assad's days "numbered" five years ago to famously promising military action if chemical weapons were used and then backing down. Syria's violence continued Monday as a Russian transport helicopter was shot down in an opposition-held part of the north of the country, killing all five crew and officers onboard. It was the Russian military's deadliest incident since entering the conflict 10 months ago. The UN, too, said Monday it was discouraged with the lack of movement toward a transition. But spokesman Farhan Haq said the world body would push for Syrian "negotiations than can accomplish something" by the end of the month.