"I join the Catholic Church in mourning a great religious leader whose exemplary service calls for emulation by others. I am saddened by his early demise," Uhuru said.
"In this hour of sorrow, and on behalf of the people and Kenya, I convey my deepest sympathy and heartfelt condolences to the ​Catholic church, family and friends."
The President said Korir's work for peace and understanding among Kenyans of different faiths deserves the warmest commendation.
"The Bishop discharged his duties of leadership with great distinction."
The late bishop played a key role in the restoration of peace in the North Rift following the 2007/8 post-election violence.
Deputy President William Ruto said described Korir as an icon of peace.
"Bishop Korir dedicated his life to preaching peaceful coexistence and harmonious relationships among communities," Ruto said. "He was an adored, respected and revered church elder whose wise counsel was sought by his flock and the country at large."
He said the cleric leaves a rich legacy of sowing the seeds of love, friendship and brotherhood.
A MORAL LIGHT
In a statement, Opposition leader Raila Odinga and Mama Ida mourned a "dear friend and a sober and reflective of voice of the Catholic Church in Kenya".
"As Bishop of the Eldoret Diocese, Bishop Korir has been one of our nation's leading moral lights and voices of reason, who also did outstanding work with many communities, and through such service touched the lives of countless Kenyans," Raila said.
"We will forever appreciate that within the Diocese of Eldoret, Bishop Korir promoted both spiritual empowerment and economic development through his numerous community organisations and charitable efforts."
The NASA leader said Korir's gentleness and humble determination, which were used to address Kenya's most pressing challenges, cannot be replaced.
He and his wife prayed that Korir's spirit lives on in the people he touched.
NATIONAL PEACEMAKER
UK High Commissioner to Kenya Nic Hailey said he was "very saddened" and described the late as a child of God.
"Blessed are the peacemakers for they will be called children of God," he wrote on Twitter.
The leaders' sentiments were echoed by governors who termed Korir a national peacemaker who preached inter-tribal harmony.
Council of Governor Chairman Josphat Nanok (Turkana) said at the national level, Korir was instrumental in stabilising the country.
"He was a local and national peacemaker among the warring pastoralist communities in Northern Kenya," he said.
Nanok further said the bishop bequeathed humanity, deep compassion, education, peace and care for the less fortunate.
"He was an unsung hero whose selfless actions touched many lives. With his passing on, humankind is poorer," the Governor said.
"On behalf of the Council of Governors and the 47 county governments, my thoughts and prayers are with you and family at this difficult moment in time."
-The Star/PATRICK VIDIJA