Former US president Bill Clinton has said he fell in love with Belfast over the course of his “comings and goings of the last 23 years” in trying to secure and protect a peace agreement for Northern Ireland.

Mr Clinton and former US senator George Mitchell on Tuesday night received the Freedom of the City of Belfast following a day of events to mark the 20th anniversary of the Belfast Agreement.

The pair had the civic honour conferred on them by the local council to acknowledge the role they had played in helping to seal the 1998 peace accord.

Lord Mayor of Belfast Nuala McAllister told them they had “helped to bring our communities together and paved the way for a brighter future for generations to come”.

In his acceptance speech after signing the freeman register, Mr Clinton told an audience of dignitaries and members of the public, who had applied for tickets for the “Our Home is Your Home” ceremony, that he had fallen in love with Belfast amid the “comings and goings of the last 23 years”.

“Do not give up the freedom the peace agreement has brought,” he said. He also challenged Northern Irish society to “give the same gift to generations yet to come”. He said he wanted everyone to protect peace, freedom, democracy and shared opportunities.

“Don’t give it up,” he said.

Mr Mitchell said no award he had ever received meant more to him than being given the Freedom of Belfast. The former peace envoy said large part of his heart would always be with the people of Northern Ireland.

An older woman in the audience told The Irish Times she had applied for a ticket as she had “great respect” for both men, while a 40-year-old woman said she had brought her 11-year-old son with her to let him see for himself what was “a part of our history”.

What we can take away from today is that if we can get over what seemed like insurmountable issues 20 years ago, equality and legacy should not be impossible Politicians new and old were also in attendance, including Alliance Party leader Naomi Long, who was working as an engineer back in 1998. She said the 1994 ceasefires had got her involved in politics because she felt for the first time in her lifetime there was an opportunity for change.

“I feel a huge responsibility about where the next 20 years goes and I hope everybody else who has been at all the events, as fantastic as they are, feel not just inspired by challenged,” she said.

Equality Peace-building priest Fr Gary Donegan said he wanted to be there to celebrate as “Clinton went against the grain and gave us a chance”.

“What we can take away from today is that if we can get over what seemed like insurmountable issues 20 years ago, equality and legacy should not be impossible,” he said.

Former tánaiste and Labour leader Eamonn Gilmore, now European Union special envoy to the Colombian peace process, said it was important to mark that peace had been achieved and the fact so many people are alive who would not have been if the conflict had continued.