But halting progress, ever-more deadly drone attacks and unmoving negotiating positions seem to have taken their toll. On Thursday, Trump used a striking analogy to concede the warfare was nowhere near over, and that he did not, at that moment, feel it was best to intervene.

Asked about the comment, Kremlin spokesman Dmitry Peskov said: "Here, of course, the U.S. president may have his own point of view on what is happening, but for us this is an exis