Britain's deputy prime minister Nick Clegg will warn that the UK and Ireland need each other more than ever because of global uncertainty.
During his first official visit to Ireland to attend the British-Irish Council summit, the Liberal Democrat leader is also expected to say both countries need to stand together as equals to "lead" a European recovery.
Taoiseach Enda Kenny will host the talks involving leaders from London, Belfast, Edinburgh, Cardiff, Jersey, Guernsey and the Isle of Man at Dublin Castle.
During the trip, Mr Clegg will also have separate meetings with President Michael D Higgins, Mr Kenny, Tanaiste Eamon Gilmore and Jobs, Enterprise and Innovation Minister Richard Bruton.
In the evening, Mr Clegg will attend a reception for business leaders held in association with UK Trade & Investment and the British Chambers of Commerce. He is expected to make reference to the "historic year" in 2011 for UK and Irish relations.
"Eight months ago the symbolism and success of the Queen's visit and the warmth with which she and Prince Philip were received were recognised worldwide," the UK deputy prime minister is expected to say.
"The legacy of history has sometimes shackled our friendship. After this last historic year, surely we can say our friendship is shackled no longer. For many people, this is the closest we have been in living memory - some would say the closest we have ever been."
Mr Clegg is expected to urge even closer ties because in these "extremely uncertain times" Ireland and the UK "need each other more than ever".
"The challenges we face have brought the importance of our friendship into stark focus," he will say. "And we see clearly that so much more unites us than divides us; that we are stronger together - standing shoulder to shoulder as real and equal partners - than we are when we stand apart, and we can play our part together in leading a European recovery."
Mr Clegg and Mr Gilmore are expected to sign a Memorandum of Understanding promising even closer co-operation on consular support during international crises. The pact includes an agreement to share information on crisis planning, a staff exchange programme between the Irish Department of Foreign Affairs and Trade and the UK Foreign and Commonwealth Office and improvements in co-operation on staff consular training.