WATCH: The architects of the Good Friday Agreement have gathered in Belfast on its 20th anniversary.

By PA and Q Radio News

One of the architects of the Good Friday Agreement has said he is sad and angry at how politics in Northern Ireland sits 20 years after the landmark deal.

Former SDLP deputy first minister Seamus Mallon, who helped broker the 1998 peace accord, has accused the Democratic Unionists and Sinn Fein of creating political silos, debasing the process and "almost Balkanising" the country.

He said: "Am I sad? Yes. Am I angry? Yes, very angry. Especially when I watch television sitting in my house, just me and the dog, and I watch the hypocrisies which are unbelievable and the untruths which are believable.

"Politics has been debased and diminished by these two political silos which have almost Balkanised the Northern Ireland that I live in.

"It is the future we should be looking at."

Mr Mallon was speaking ahead of a major event marking the 20th anniversary of the agreement at Queen's University in Belfast.

Dr.Seamus Mallon recalls the dark days of the #Troubles before the Good Friday Agreement in 1998. #GFA20 He was one of the @SDLPlive negotiators pic.twitter.com/h1bfuVKXBB

— David Hunter (@davidhunter7) April 10, 2018

Senator George Mitchell, the US diplomat who chaired the negotiations, insisted there was much to celebrate despite the current political impasse at Stormont.

"Northern Ireland is a much safer, much better, much more successful place than it was 20 years ago," he said.

"The agreement did not purport to be the solution to all the problems for all time in Northern Ireland."

He said the problems facing devolution could be resolved.

"New challenges emerge," he said.

"I believe that this challenge can be met, as were the challenges of 1998, through courageous political leadership."

Senator George Mitchell praises the people of Northern Ireland and says he hopes the peace will last. #GFA20 pic.twitter.com/T2zg59o9Xk

— David Hunter (@davidhunter7) April 10, 2018

Northern Ireland has been without a functioning government since last January.

However, former Sinn Fein leader Gerry Adams has expressed confidence in the future.

He said: "The institutions will be back in place. The Good Friday Agreement remains the accord which is going to guide politics on this island and arrangements on this island and relationships on this island into the foreseeable future.

"I think the future is very bright. There is always an ebb in a process. There is always and ebb and a flow. We are in an ebb, it is temporary."

.@GerryAdamsSF was asked if the current political impasse has undermined the celebrations of #GFA20 - He says “A deal is only that” implementing and working a deal is the challenge. pic.twitter.com/Vm52Zos85w

— David Hunter (@davidhunter7) April 10, 2018