Northern Ireland Protocol issues can be fixed ahead of Good Friday Agreement landmark – Bertie Ahern

Mr Ahern said he was hopeful the anniversary of the agreement will be able to be celebrated in April with a deal on the outstanding protocol issues met.

Talks between the UK and EU to resolve the impasse over the contentious Brexit trading arrangements are continuing, with both sides insisting a deal is possible.

"The technical issues on the protocol, I believe, can be sorted out," Mr Ahern told BBC One's Sunday Politics Northern Ireland programme.

"I do understand that unionists and loyalists have concerns about the constitutional position. They do have concerns that have to be worked out and we have to take account of their views and try and find solutions to alleviate the concerns and fears. I think that's very important."

The former Fianna Fail leader said "a lot of progress" has been made on the protocol issues.

"Hopefully over the early weeks of next year that can be dealt with," Mr Ahern added.

"The concern about the constitutional issues ... we have to work through with loyalists and unionists, and that hopefully that can happen too.

"So, I'm hopeful that when we get to April, we will be able to genuinely celebrate it and not in the way it is at present."

Devolved government at Stormont has been in flux since February when the DUP withdrew its first minister from the ministerial executive in protest at Brexit's Northern Ireland Protocol.

The DUP has insisted it will not allow a return to powersharing until radical changes to the protocol are delivered.

The region's largest unionist party has blocked the formation of a new administration following May's Assembly election and prevented the Assembly meeting to conduct legislative business as part of its protest over the protocol.

It claims the protocol has undermined Northern Ireland's place within the United Kingdom by creating economic barriers on trade entering the region from Great Britain.