Carwyn Jones has suggested there could a new federal arrangement of the UK nations in the wake of the vote to leave the European Union.
The first minister said he wanted to avoid Wales being seen as "some sort of annexe to England".
Wales and England both voted to leave the EU, while majorities in Scotland and Northern Ireland voted to stay.
The discrepancy has led to calls for a fresh referendum on independence in Scotland.
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Mr Jones told the BBC's Newyddion 9: "The last thing we want is to be considered some sort of annexe to England.
"We don't have to have independence - there is a way to ensure there is some sort of federation, or some sort of agreement.
"That doesn't mean you have to have independence."
But Mr Jones rejected calls from Plaid Cymru leader Leanne Wood for Wales to become an independent state within the EU, saying the people of Wales had voted to leave the union.
The first minister has floated the idea of a federal UK in the past, notably in a speech in October 2014 where he said: "Enabling unity while guaranteeing diversity is precisely the challenge we face.
"In other words, striking the best balance between national citizenship and local flexibility. Federal thinking gives us a new starting point to challenge the way we habitually view the state."