The unannounced visit comes amid escalating war in Ethiopia's north and just ahead of US secretary of state’s visit to Kenya.
Kenyan President Uhuru Kenyatta has arrived in unannounced in Ethiopia primarily for security talks.
Kenyatta's visit to the capital Addis Ababa on Sunday comes amid an escalation in a yearlong war in northern Ethiopia between the Ethiopian armed forces and forces of the Tigray People's Liberation Front (TPLF).
It also precedes the scheduled visit of US Secretary of State Antony Blinken to Kenya, Nigeria and Senegal from November 15-20.
President Kenyatta was the subject of controversy after winning 2017 elections by a margin of 98 percent with low turnout. Kenya will face elections in 9 months.
The Kenyan president was also identified in the Pandora Papers as a beneficiary of an offshore secret account by the International Consortium of Investigative Journalists following an investigation involving 600 journalists from 150 media outlets in 117 countries.
There has been mounting pressure and calls by the US and UN for the warring parties to immediately and without precondition end the war and start dialogue. War has been raging since November last year with no end in sight after TPLF forces attacked Ethiopia's federal army bases stationed across Tigray.
The UN and the African Union’s Special Envoy for the Horn of Africa, former Nigerian president Olusegun Obasanjo, have warned of a short window of opportunity for the cessation of hostilities and dialogue.
Upon his arrival at Addis Ababa Bole International Airport, Kenyatta was welcomed by Prime Minister Abiy Ahmed and President Sahle-Work Zewde.
US Secretary of State Blinken is set to meet the Kenyan president during his visit.
"The secretary and representatives of the Kenyan government will discuss our shared interests as members of the UN Security Council, including addressing regional security issues such as Ethiopia, Somalia and Sudan," according to a US State Department press statement on Thursday by spokesperson Ned Price.
Ethiopia and Kenya enjoy friendly relations and strong trade ties that were recently further cemented by the inauguration of the first phase of joint Lamu Port-South Sudan-Ethiopia Transport Corridor infrastructure project.
The multibillion dollar-project aims to link Kenya, Ethiopia, Uganda and South Sudan via highways and railways to facilitate more trade via a Kenyan port.