The Archbishop of Canterbury is set to host a meeting of the 39 primates from across the world.
It'll be the first meeting of its kind since the January 2016 meeting in which there was said to be much conflict on the issue of sexuality.
The Archbishops of Nigeria (pictured below) and Uganda have already confirmed that they won't attend because of their belief that not enough progress has been made on the subject since that meeting.
In a new video posted on the Anglican Communion web site, Justin Welby says he will miss those who don't attend through illness or because of objections.
He said: "It's such a privilege to have these meetings, to have all the leaders gather together to pray, encourage one another, weep with one another, celebrate with one another.
"We'll have 16 new primates since January 2016 and there will be a whole lot of fresh energy and no doubt some fresh questions.
"We will miss those who are not there and I am aware that possibly as many as 6, possibly less will not be there either through health or because they've chosen not to be at the moment."
Hinting at his disappointment at those who have chosen not to attend, he said: "In January 2016 we spent a week in Canterbury in what was one of the most memorable weeks of my life.
"The key thing that came out was a unanimous vote from those present that we would walk together. It might be at a slight distance but we would walk together."