The chair of the Iraq war inquiry has announced a long-awaited timetable for publication of the report — promising Britain's prime minister it will be out in June or July 2016.

John Chilcot's pledge to Prime Minister David Cameron comes after months of pressure to complete the investigation, which began in 2009. The inquiry into decisions and mistakes in Britain's planning and execution of the war has been delayed in part by a process that gives those who are criticized a chance to respond.

Families of military personnel killed in Iraq had threatened to go to court, saying the delays were prolonging their suffering.

Chilcot says in a letter released Thursday that the report will first be given to a panel that will check sensitive national security material.