He described this as the "key outcome" from last week's report by the House of Bishops on human sexuality.
It said that whilst the Church needs to clarify the pastoral support for LGBT people it would not recognise same sex marriages.
In his letter Archbishop Justin set out his vision for the next Primates' Meeting, which will take place in Canterbury in October.
He said it was an opportunity for relaxed fellowship and mutual consultation and invited all primates to submit items they want to discuss.
"I certainly feel the need to be with you, to share our experience and in prayer and fellowship, to support one another and seek how best we can serve the call to preach the gospel, serve the poor and proclaim the Kingdom of God," he wrote.
It's the first meeting of all 38 primates since their discussions at the start of 2016 which drew worldwide attention.
The US-based Episcopal Church was reprimanded at that meeting for its acceptance of same sex marriage.
