RTÉ's retiring northern editor Tommie Gorman was an essential part of the Northern Ireland peace process, the Taoiseach said.
His versatility and wisdom shone through as he reported with humanity on the possibilities politics offered and the compromises required, Micheál Martin added.
Gorman's employer said he was the "beating heart" of RTÉ News after announcing the journalist from Sligo will step down this spring after 41 years with the broadcaster.
"Tommie Gorman is the quintessential professional who earned the trust of all who dealt with him," Mr Martin said.
"He understood better than most the possibilities politics offered and the compromises required to make progress.
"He brought us the daily news of an unfolding peace process. He was an essential part of that process."
Gorman was RTÉ's Europe editor before moving to Belfast in 2001.
He interviewed Roy Keane after the footballer's row with manager Mick McCarthy in Ireland's 2002 World Cup training camp on the island of Saipan.
He also tracked down Seamus Heaney on a Greek island after the poet had been awarded the Nobel Prize for Literature.
Diagnosed with cancer in 1994, Gorman said: "Ever since my diagnosis, work has been the ultimate distraction. You can lose yourself in work, you can lose yourself in living. You need to engage in living."
He has chronicled the ups and downs of the peace process for two decades.
Stormont First Minister Arlene Foster said Gorman always encouraged others facing difficult circumstances following his own public health challenges.
She said he tried to understand what made political leaders like her tick.
"I will miss Tommie incredibly from the political world, but of course I do consider him a friend, and that will continue," she said.
SDLP leader Colum Eastwood said: "Tommie has given decades of selfless service to the people of this island."
The Taoiseach said Gorman's knowledge of detail and command of his subjects was unequalled.
"He has left a powerful journalistic legacy underlining the centrality of accuracy, humanity and trust," Mr Martin said.
RTÉ's northern correspondent Vincent Kearney will take over as editor.