ABC News reports: Secretary of State John Kerry has said the United States and Russia have agreed to “concrete steps” for trying to revive a crumbling ceasefire in Syria, following a day of marathon talks in Moscow.

Neither side would share details, but Kerry’s announcement appeared to suggest that Russia and the U.S. reached a preliminary deal to coordinate airstrikes together against jihadist groups in Syria, potentially representing a major shift in U.S. policy in the conflict.

Kerry made the announcement alongside his Russian counterpart, Sergey Lavrov, at a news conference in Moscow after the lengthy discussions that stretched throughout Thursday.

Before the talks, the Washington Post leaked a proposal document allegedly outlining what Kerry would offer to Russia. State Department officials have indicated the document was authentic, while declining to comment directly on it.

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