In his capacity as a Deputy Speaker of Parliament , Reiner temporarily assumed the powers and duties of the President of Croatia on 11 July 2018 when , due to the rare simultaneous absence of both President Kolinda Grabar-Kitarović , who was attending the 2018 NATO summit in Brussels , and Speaker of Parliament Gordan Jandroković , who ( along with Prime Minister Andrej Plenković ) was attending the semi-finals of the 2018 World Cup in Moscow , he was left as the highest-ranking official eligible to take up the responsibility . Namely , the Constitution of Croatia allows the President of the Republic to temporarily delegate his or her powers and duties to the Speaker of Parliament during periods of absence , illness or incapacity , while the Speaker himself is likewise authorized by Article 34 of the rule book of Parliament to further delegate his or her own powers and duties to the Deputy Speakers from the parliamentary majority . As the other two eligible Deputy Speakers , Milijan Brkić ( HDZ ) and Furio Radin ( Italian national minority ) , were both also absent from the country , Reiner was left as the only possible choice to carry out the functions of head of state . Upon Jandroković 's return to Croatia the following day , Reiner ceased to carry out the powers and duties of the presidency , which reverted to the Speaker
2018 NATO summit in Brussels
2018 Brussels summit
Željko Reiner