The Archbishops of Canterbury and York have written to the presidents of Uganda and Nigeria, after being asked about laws there penalising gay people.
The letter said homosexual people were loved and valued by God and should not be victimised or diminished.
Uganda and Nigeria have both passed legislation targeting people with same-sex attraction.
The letter is also addressed to all primates (heads of national Churches) in the worldwide Anglican Communion.
Archbishops Justin Welby of Canterbury and John Sentamu of York said the letter was a result of "questions about the Church of England's attitude to new legislation in several countries that penalises people with same-sex attraction".
The letter comes as Archbishop Welby starts a five-day tour of Africa.
In Nigeria this month, President Goodluck Jonathan signed into law a bill which bans same-sex marriages, gay groups and shows of same-sex public affection.
In Uganda - Archbishop Sentamu's native country - a bill allowing for greater punishments for gay people, and those who fail to turn them in to police, has been passed by parliament, but blocked - for now - by President Yoweri Museveni.
The laws have been heavily criticised by gay and human rights groups.
UN human rights chief Navi Pillay described the Nigerian law as "draconian".
She said she had rarely seen a piece of legislation "that in so few paragraphs directly violates so many basic, universal human rights".
In their letter, the archbishops reiterated their support for a document known as the Dromantine Communique, published in 2005 by the primates of the Anglican Communion.
The communique said: "We continue unreservedly to be committed to the pastoral support and care of homosexual people.
"The victimisation or diminishment of human beings whose affections happen to be ordered towards people of the same sex is anathema to us.
"We assure homosexual people that they are children of God, loved and valued by Him and deserving the best we can give - pastoral care and friendship."
Archbishop Welby's stance on homosexual relationships has created tension with more traditionalist Anglicans.
Last October, he held talks with members of the Global Anglican Future Conference (Gafcon), which condemns those who preach what it calls a "false gospel" claiming God's blessing for same-sex unions.
The primates of seven national Anglican churches in Africa attended October's Gafcon meeting, including Uganda and Nigeria.
Archbishop Welby has said some gay couples have loving, stable and monogamous relationships of "stunning" quality.
But he says he still supports the Church of England's opposition to active homosexuality.