ROME — Countries prepared to provide troops for a post-cease-fire force in Ukraine agreed to set up a headquarters in Paris for a rapid deployment after hostilities end in Russia's war on its neighbor. A U.S. delegation was present for the first time at a meeting of the group on Thursday. Retired Lt. Gen. Keith Kellogg , U.S. President Donald Trump’s special envoy for Ukraine and Russia, was on hand for the meeting, which took place on the sidelines of the fourth annual conference on Ukraine’s