• In the United States, the debate turned acrid over President Trump’s condolence call to the widow of Sgt. La David T. Johnson, above, one of four soldiers killed in Niger this month.

Sergeant Johnson’s mother said that Mr. Trump did, in fact, tell his widow that he “knew what he signed up for.” The president has denied this. Several families of fallen soldiers said that they had not heard from the president.

Separately, Attorney General Jeff Sessions testified before the Senate Judiciary Committee, but refused to discuss his conversations with Mr. Trump about Russia or the firing of James Comey, the former F.B.I. director.