Ruto, who retained one serving cabinet secretary, appointed former deputy prime minister Musalia Mudavadi as the prime cabinet secretary, a newly created position.
He also appointed the former Central Bank of Kenya (CBK) Governor Njuguna Ndung’u to be the cabinet secretary for the National Treasury.
Ruto, who nominated current and former lawmakers to the Cabinet, said the prime cabinet secretary’s office is the most senior after that of the President and deputy president’s office.
Ruto told a televised news conference in Nairobi, the Kenyan capital, that the prime cabinet secretary will assist the deputy president and the president in liaison with the interior ministry.
"He will oversee the government projects. He will coordinate the national legislative agenda," Ruto said.
The president also appointed former Machakos County Governor Alfred Mutua to be the cabinet secretary for Foreign Affairs and Kithure Kindiki, former Senate deputy speaker, as the cabinet secretary for Interior.
According to the Constitution, Kenya’s Cabinet should contain no fewer than 14 but no more than 22 cabinet secretaries.
Ruto also appointed former National Assembly Speaker Justin Muturi as the Attorney General, Mercy Wanjau as secretary to the Cabinet, and Monica Juma, who was the serving cabinet secretary for Energy in the previous government, as National Security adviser.
The nominees will be subjected to vetting by the National Assembly.
The president also announced the resignation of Inspector-General of Police Hilary Mutyambai who he said has proceeded on terminal leave and the resignation of the head of the Directorate of Criminal Investigations George Kinoti.
"After discussing with Mutyambai, I have accepted his terminal leave," Ruto said.
Ruto said Kinoti has formally resigned, having served as the country’s top detective under former President Uhuru Kenyatta.
The president said he will pick someone to act in the place of Kinoti as his replacement awaits.