Speaking at a dinner in Washington during a Christian-Muslim conference, Dr Williams told the guests that coming together meant addressing their differences seriously, but always in the context of their shared challenges.

"We have recognised that we have a common agenda; we can't always say that we have identical convictions and certainly aren't aiming to iron out the differences and the difficulties of our convictions but this is a world in which no one religious community, no one nation, no one interest group can solve problems alone... The ecological crisis that our planet faces is one that is no respecter of religious difference and there is one planet on which we live, global warming is theologically uneducated; rising water levels do not discriminate between Christians, Muslims, Jews or anyone else."

Guests at the dinner, including Arab ambassadors based in Washington, also heard Dr Williams describe as 'outrageous, unjust and exceptional' the death sentence passed on an Afghan Christian who had converted from Islam.

"None of us could have imagined how topical the work of our conference would seem in the light of the very complex and tragic situation in Afghanistan, with the death sentence threatened to a Christian convert there."

Dr Williams warned against adopting cultural stereotypes in trying to approach such situations. The challenge, he said was to earn trust:

"It's not just a matter of the Islamic world being asked to adopt uncritically a 'Western-model', secular human rights framework with all the conceptual and practical problems that entails, but working out what it would be like to live in a world where different societies recognised the credibility, the justice and the legitimacy in each other because there were certain things they could be secure about; certain areas where they did not think they would come up against outrageous, unjust and exceptional threats such as the Afghan incident represents."