Kuwait's cabinet has started procedures to transfer power to Prime Minister Sheikh Sabah al-Ahmad because of the ill health of the new emir.
The prime minister has been running the country for many years
The move comes amid conflict over who should lead Kuwait, following the death of Emir Jaber al-Ahmad six days ago.
Emir Sheikh Saad al-Abdullah has said he wants to take the oath of office.
But according to Kuwait's constitution, parliament can declare the emir's post vacant if it decides by a two-thirds majority he is too unwell to govern.
In a statement to parliament, the cabinet said it had decided to invoke a law that allows it to appoint a medical team to examine Sheikh Saad's fitness to rule.
Under the law, if the emir "loses the physical ability to perform his duties", the cabinet can take the matter to parliament.
The emergency cabinet meeting came only shortly after the new emir told parliament he wanted to take office himself.
As crown prince during Sheikh Jaber's long rule, Sheikh Saad automatically became the new emir on his death.
The new emir (right) has been in poor health for several years
But his ongoing ill health has led to severe doubts about whether he will even be able to take the two-line oath of office in parliament, let alone lead.
For the swearing-in, the emir takes the podium in parliament, whose ceremonial sessions are usually televised, and recites a two-line oath vowing to respect the constitution and safeguard the country.
Sheikh Saad, 75, has yet to name his own crown prince, adding to the uncertainty over the succession.
The prime minister, who has governed Kuwait on a day-to-day basis for several years, was asked to take the role of de facto leader by the country's ruling family on Friday.
State television has reported that many members of the ruling family are backing plans for Sheikh Sabah to take power despite the emir's apparent unwillingness to stand down.