Kuwaiti Prime Minister-designate Sheikh Ahmad Abdullah Al-Ahmad Al-Sabah was sworn in on Sunday as the emir's deputy.
The move followed a decree issued by Emir Sheikh Mishal Al-Ahmad Al-Jaber Al-Sabah appointing Sheikh Ahmad as his deputy when he is abroad, the state news agency KUNA reported.
The emir, who was sworn in in December, has yet to choose a crown prince, who would usually be his deputy.
Sheikh Ahmad was appointed by the country's ruler as prime minister after the government's resignation earlier this month.